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1. Early Universe Thermodynamics and Evolution in Nonviscous and Viscous Strong and Electroweak Epochs: Possible Analytical Solutions

Author: Abdel Nasser Tawfik and Carsten Greiner
Subjects: viscous cosmology, particle-theory and field-theory models of the early universe, mathematical and relativistic aspects of cosmology, thermodynamic functions and equations of state, Science, Astrophysics, QB460-466, Physics, QC1-999
Abstract: Based on recent perturbative and non-perturbative lattice calculations with almost quark flavors and the thermal contributions from photons, neutrinos, leptons, electroweak particles, and scalar Higgs bosons, various thermodynamic quantities, at vanishing net-baryon densities, such as pressure, energy density, bulk viscosity, relaxation time, and temperature have been calculated up to the TeV-scale, i.e., covering hadron, QGP, and electroweak (EW) phases in the early Universe. This remarkable progress motivated the present study to determine the possible influence of the bulk viscosity in the early Universe and to understand how this would vary from epoch to epoch. We have taken into consideration first- (Eckart) and second-order (Israel–Stewart) theories for the relativistic cosmic fluid and integrated viscous equations of state in Friedmann equations. Nonlinear nonhomogeneous differential equations are obtained as analytical solutions. For Israel–Stewart, the differential equations are very sophisticated to be solved. They are outlined here as road-maps for future studies. For Eckart theory, the only possible solution is the functionality, H(a(t)), where H(t) is the Hubble parameter and a(t) is the scale factor, but none of them so far could to be directly expressed in terms of either proper or cosmic time t. For Eckart-type viscous background, especially at finite cosmological constant, non-singular H(t) and a(t) are obtained, where H(t) diverges for QCD/EW and asymptotic EoS. For non-viscous background, the dependence of H(a(t)) is monotonic. The same conclusion can be drawn for an ideal EoS. We also conclude that the rate of decreasing H(a(t)) with increasing a(t) varies from epoch to epoch, at vanishing and finite cosmological constant. These results obviously help in improving our understanding of the nucleosynthesis and the cosmological large-scale structure.
Published: 2021
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2. Type IV singular bouncing cosmology from f(T) gravity.

Author: Logbo, P. H. and Houndjo, M. J. S.
Subjects: *GRAVITY, *HUBBLE constant, *ASTROPHYSICS, *FRIEDMANN equations
Abstract: We investigate bouncing scenario in the modified f (T) gravity, T being the torsion scalar. Attention is attached to the reconstruction of f (T) able to describe type IV singular bouncing evolution, where we adopt as assumption that the bouncing and type IV singularity points coincide. In the context of the reconstructed f (T) model, we calculate the Hubble slow-roll parameters in order to determine the dynamical evolution of the cosmological system under study. The results show that the Hubble slow-roll parameters become singular at the type IV singularity indicating a dynamical instability. Moreover, we perform the stability analysis of the f (T) gravity solution where, according to the obtained result, the type IV singularity point is a saddle point in agreement with the bounce scenario. [ABSTRACT FROM AUTHOR]
Published: 2019
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3. Inflationary Cosmology in Modified Gravity Theories

Author: Kazuharu Bamba and Sergei D. Odintsov
Subjects: dark energy, cosmology, particle-theory and field-theory models of the early Universe, modified theories of gravity, models beyond the standard model, loop quantum gravity, quantum geometry, spin foams, mathematical and relativistic aspects of cosmology, Mathematics, QA1-939
Abstract: We review inflationary cosmology in modified gravity such as R2 gravity with its extensions in order to generalize the Starobinsky inflation model. In particular, we explore inflation realized by three kinds of effects: modification of gravity, the quantum anomaly, and the R2 term in loop quantum cosmology. It is explicitly demonstrated that in these inflationary models, the spectral index of scalar modes of the density perturbations and the tensor-to-scalar ratio can be consistent with the Planck results. Bounce cosmology in F(R) gravity is also explained.
Published: 2015
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4. Periodic Cosmological Evolutions of Equation of State for Dark Energy

Author: Ratbay Myrzakulov, Gulgasyl Nugmanova, Petr Tsyba, Kuralay Yesmakhanova, Kazuharu Bamba, and Ujjal Debnath
Subjects: dark energy, cosmology, particle-theory and field-theory models of the early universe, Science, Astrophysics, QB460-466, Physics, QC1-999
Abstract: We demonstrate two periodic or quasi-periodic generalizations of the Chaplygin gas (CG) type models to explain the origins of dark energy as well as dark matter by using the Weierstrass ξ(t), σ(t) and ζ (t) functions with two periods being infinite. If the universe can evolve periodically, a non-singular universe can be realized. Furthermore, we examine the cosmological evolution and nature of the equation of state (EoS) of dark energy in the Friedmann–Lemaître–Robertson–Walker cosmology. It is explicitly illustrated that there exist three type models in which the universe always stays in the non-phantom (quintessence) phase, whereas it always evolves in the phantom phase, or the crossing of the phantom divide can be realized. The scalar fields and the corresponding potentials are also analyzed for different types of models.
Published: 2012
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5. A Stringent Limit on Variation of the Fine-Structure Constant Using Absorption Line Multiplets in the Early Universe.

Author: Le, T.
Subjects: *ABSORPTION, *PHYSICAL cosmology, *FINE-structure constant, *PHYSICAL constants, *ASTROPHYSICS research
Abstract: One of the key questions of modern physics concerns the possibility that physical constants have varied throughout the history of the Universe. The standard model of physics is built on these constants, but it does not provide any explanation for their values, nor does it require their constancy over space and time. Here, we set a new limit on possible spatial and temporal variations of the fine-structure constant α = e/4πε ħc by comparing transitions and line multiplets in an ensemble of Fe II λ 1608, λ 2344, λ 2374, λ 2383, λ 2587, and λ 2600 observed in the early Universe with those measured in the laboratory. Based on the optical spectrum observations of QSO HE 0515-4414, we deduce a constraint of Δα/α = (-0.157± 0.300)×10 at redshift z = 1.15. At present, this represents the tightest limit on Δα/α in early cosmological epochs compared to the published results in the literature. [ABSTRACT FROM AUTHOR]
Published: 2016
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6. Recent results and perspectives on cosmology and fundamental physics from microwave surveys.

Author: Burigana, Carlo, Battistelli, Elia Stefano, Benetti, Micol, Cabass, Giovanni, De Bernardis, Paolo, Di Serego Alighieri, Sperello, Di Valentino, Eleonora, Gerbino, Martina, Giusarma, Elena, Gruppuso, Alessandro, Liguori, Michele, Masi, Silvia, Norgaard-Nielsen, Hans Ulrik, Rosati, Piero, Salvati, Laura, Trombetti, Tiziana, and Vielva, Patricio
Subjects: *COSMIC background radiation, *POLARIZATION (Nuclear physics), *STANDARD model (Nuclear physics), *GAUSSIAN function, *METAPHYSICAL cosmology, *MATHEMATICAL models, UNIVERSE
Abstract: Recent cosmic microwave background (CMB) data in temperature and polarization have reached high precision in estimating all the parameters that describe the current so-called standard cosmological model. Recent results about the integrated Sachs-Wolfe (ISW) effect from CMB anisotropies, galaxy surveys, and their cross-correlations are presented. Looking at fine signatures in the CMB, such as the lack of power at low multipoles, the primordial power spectrum (PPS) and the bounds on non-Gaussianities, complemented by galaxy surveys, we discuss inflationary physics and the generation of primordial perturbations in the early universe. Three important topics in particle physics, the bounds on neutrinos masses and parameters, on thermal axion mass and on the neutron lifetime derived from cosmological data are reviewed, with attention to the comparison with laboratory experiment results. Recent results from cosmic polarization rotation (CPR) analyses aimed at testing the Einstein equivalence principle (EEP) are presented. Finally, we discuss the perspectives of next radio facilities for the improvement of the analysis of future CMB spectral distortion experiments. [ABSTRACT FROM AUTHOR]
Published: 2016
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7. Kaluza-Klein reduction and Bergmann-Wagoner bi-scalar general action of scalar-tensor gravity.

Author: Bamba, Kazuharu, Momeni, Davood, and Myrzakulov, Ratbay
Subjects: *KALUZA-Klein theories, *SCALAR field theory, *TENSOR algebra, *SPACETIME, *STABILITY theory
Abstract: We examine the Kaluza-Klein (KK) dimensional reduction from higher dimensional space-time and the properties of the resultant Bergmann-Wagoner general action of scalar-tensor theories. With the analysis of the perturbations, we also investigate the stability of the anti-de Sitter (AdS) space-time in the (D ∈ 풩)-dimensional Einstein gravity with the negative cosmological constant. Furthermore, we derive the conditions for the dimensional reduction to successfully be executed and present the KK compactification mechanism. [ABSTRACT FROM AUTHOR]
Published: 2015
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8. Inflationary Cosmology in Modified Gravity Theories.

Author: Bamba, Kazuharu and Odintsov, Sergei D.
Subjects: *INFLATIONARY universe, *QUANTUM cosmology, *GRAVITATION, *SCALAR field theory, *PLANCK'S constant
Abstract: We review inflationary cosmology in modified gravity such as R² gravity with its extensions in order to generalize the Starobinsky inflation model. In particular, we explore inflation realized by three kinds of effects: modification of gravity, the quantum anomaly, and the R² term in loop quantum cosmology. It is explicitly demonstrated that in these inflationary models, the spectral index of scalar modes of the density perturbations and the tensor-to-scalar ratio can be consistent with the Planck results. Bounce cosmology in F(R) gravity is also explained. [ABSTRACT FROM AUTHOR]
Published: 2015
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9. Unified scenario of three types of neutrinos with respective mass scales.

Author: Nishio, Sakiko G. J., Bamba, Kazuharu, and Sugamoto, Akio
Subjects: *NEUTRINO mass, *KALUZA-Klein theories, *SPACETIME, *DARK matter, *FIELD theory (Physics), UNIVERSE
Abstract: A unified theory of three different types of neutrinos is discussed in the Kaluza-Klein (KK) five-dimensional spacetime theory. In particular, we construct the scenario in which the zeroth KK modes correspond to the left-handed neutrinos with the meV mass and the right-handed sterile neutrinos with the keV mass, whereas the first KK modes to the neutrinos with the TeV mass. [ABSTRACT FROM AUTHOR]
Published: 2014
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10. Early Universe Thermodynamics and Evolution in Nonviscous and Viscous Strong and Electroweak Epochs: Possible Analytical Solutions

Author: Tawfik, Abdel Nasser and Greiner, Carsten
Subjects: 98.80.Cq, High Energy Physics::Phenomenology, thermodynamic functions and equations of state, MathematicsofComputing_GENERAL, 05.70.Ce, FOS: Physical sciences, lcsh:Astrophysics, General Relativity and Quantum Cosmology (gr-qc), Astrophysics::Cosmology and Extragalactic Astrophysics, 98.80.Jk, mathematical and relativistic aspects of cosmology, Computer Science::Digital Libraries, lcsh:QC1-999, General Relativity and Quantum Cosmology, Article, particle-theory and field-theory models of the early universe, 98.80.-k, lcsh:QB460-466, Computer Science::Programming Languages, lcsh:Q, ddc:530, viscous cosmology, lcsh:Science, lcsh:Physics
Abstract: Based on recent perturbative and non-perturbative lattice calculations with almost quark flavors and the thermal contributions from photons, neutrinos, leptons, electroweak particles, and scalar Higgs bosons, various thermodynamic quantities, at vanishing net-baryon densities, such as pressure, energy density, bulk viscosity, relaxation time, and temperature have been calculated up to the TeV-scale, i.e. covering hadron, QGP and electroweak (EW) phases in the early Universe. This remarkable progress motivated the present study to determine the possible influence of the bulk viscosity in the early Universe and to understand how this would vary from epoch to epoch. We have taken into consideration first- (Eckart) and second-order (Israel-Stewart) theories for the relativistic cosmic fluid and integrated viscous equations of state in Friedmann equations. Nonlinear nonhomogeneous differential equations are obtained as analytical solutions. For Israel-Stewart, the differential equations are very sophisticated to be solved. They are outlined here as road-maps for future studies. For Eckart theory, the only possible solution is the functionality, $H(a(t))$, where $H(t)$ is the Hubble parameter and $a(t)$ is the scale factor, but none of them so far could to be directly expressed in terms of either proper or cosmic time $t$. For Eckart-type viscous background, especially at finite cosmological constant, non-singular $H(t)$ and $a(t)$ are obtained, where $H(t)$ diverges for QCD/EW and asymptotic EoS. For non-viscous background, the dependence of $H(a(t))$ is monotonic. The same conclusion can be drawn for an ideal EoS. We also conclude that the rate of decreasing $H(a(t))$ with increasing $a(t)$ varies from epoch to epoch, at vanishing and finite cosmological constant. These results obviously help in improving our understanding of the nucleosynthesis and the cosmological large-scale structure., 27 pages, 5 figures, accepted for publication in ENTROPY
Published: 2021

11. Tev Scale Colored Particles, Baryogenesis and Dark Matter.

Author: Nasri, Salah
Subjects: *PARTICLES (Nuclear physics), *DARK matter, *INTERSTELLAR medium, *SCALAR field theory, *CALCULUS of tensors
Abstract: We propose a unified scenario of two puzzles in particle physics and cosmology, namely, the dark matter and the origin of the baryon asymmetry of the universe in a simple extension of MSSM. Our model uses a gauge singlet chiral superfield field N, where the out–of equilibrium decay of the fermionic partner of N mediated by the exchange of a colored TeV scale scalar field generates adequate baryon asymmetry for MN∼100 GeV. The scalar partner of N is naturally the lightest SUSY particle as it has no gauge interactions and plays the role of dark matter. The model is experimentally testable in (i) neutron–antineutron oscillations with a transition time estimated to be around 1010 sec, (ii) discovery of colored particles X at LHC with mass of order TeV, and (iii) direct dark matter detection with a predicted cross section in the observable range in next generation dark matter search experiments. [ABSTRACT FROM AUTHOR]
Published: 2008
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12. Periodic Cosmological Evolutions of Equation of State for Dark Energy.

Author: Bamba, Kazuharu, Debnath, Ujjal, Yesmakhanova, Kuralay, Tsyba, Petr, Nugmanova, Gulgasyl, and Myrzakulov, Ratbay
Subjects: *DARK energy, *METAPHYSICAL cosmology, *GENERALIZATION, *DARK matter, *WEIERSTRASS points, *EQUATIONS of state, *FRIEDMANN equations, *SCALAR field theory
Abstract: We demonstrate two periodic or quasi-periodic generalizations of the Chaplygin gas (CG) type models to explain the origins of dark energy as well as dark matter by using the Weierstrass ...(t), σ(t) and ζ(t) functions with two periods being infinite. If the universe can evolve periodically, a non-singular universe can be realized. Furthermore, we examine the cosmological evolution and nature of the equation of state (EoS) of dark energy in the Friedmann-Lemaître-Robertson-Walker cosmology. It is explicitly illustrated that there exist three type models in which the universe always stays in the non-phantom (quintessence) phase, whereas it always evolves in the phantom phase, or the crossing of the phantom divide can be realized. The scalar fields and the corresponding potentials are also analyzed for different types of models. [ABSTRACT FROM AUTHOR]
Published: 2012
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13. ABELIAN GAUGE THEORY IN DE SITTER SPACE.

Author: ROUHANI, S. and TAKOOK, M. V.
Subjects: *SPINOR analysis, *VECTOR fields, *VECTOR analysis, *ABELIAN groups, *GROUP theory, *GREEN'S functions
Abstract: Quantization of spinor and vector free fields in four-dimensional de Sitter spacetime, in the ambient space notation, has been studied in the previous works. Various two-point functions for the above fields are presented in this paper. The interaction between the spinor field and the vector field is then studied by the Abelian gauge theory. The U(1) gauge invariant spinor field equation is obtained in a coordinate independent way notation and their corresponding conserved currents are computed. The solution of the field equation is obtained by the use of the perturbation method in terms of the Green's function. The null curvature limit is discussed in the final stage. [ABSTRACT FROM AUTHOR]
Published: 2005
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14. Systematic QSOs emission line shifts caused by a high-temperature mechanism.

Author: Yao, Qiankai and Feng, Mang
Abstract: The observed results exhibit the fact that there are some systematic effects in QSOs spectra, such as: a) the different emission lines give different red-shifts; b) high-ionization lines (HILs) CIV λ1549, NV, CIII] X.1909 and possibly Ly are systematically blue-shifted to a velocity of about 600 km s with respect to low-ionization lines (LILs) 01, Mgll λ2798 and the balmer lines; c) a systematic red-shift of CIII] to CIV has also been found to correlate in a linear fashion with the red-shift difference between the MgII and CIV. Until now, these effects have not been understood. The motivation of this paper was to present a new mechanism to discuss these effects. [ABSTRACT FROM AUTHOR]
Published: 1996
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15. Non-singular viscous universe with decaying vacuum energy.

Author: Arbab, A. and Abdel-Rahman, A.
Abstract: The effect of bulk viscosity on decaying vacuum cosmologies is investigated in a non-singular scenario. The considered model describes a closed universe exhibiting several features of previously proposed non-viscous cosmologies. In particular, it predicts that nucleosynthesis proceeds as in the standard model provided the Universe today is matter-dominated. [ABSTRACT FROM AUTHOR]
Published: 1996
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16. Recent results and perspectives on cosmology and fundamental physics from microwave surveys

Author: Carlo, Burigana, Battistelli, Elia Stefano, Micol, Benetti, Cabass, Giovanni, DE BERNARDIS, Paolo, Sperello Di Serego Alighieri, Eleonora Di Valentino, Gerbino, Martina, Elena, Giusarma, Alessandro, Gruppuso, Michele, Liguori, Masi, Silvia, Hans Ulrik Norgaard Nielsen, Piero, Rosati, Laura, Salvati, Tiziana, Trombetti, Patricio, Vielva, Benetti, Micol, DI VALENTINO, Eleonora, Giusarma, Elena, Salvati, Laura, Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Agenzia Spaziale Italiana, Istituto Nazionale di Astrofisica, Institut d'Astrophysique de Paris ( IAP ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Bianchi, Massimo, Jantzen, Robert T., and Ruffini, Remo
Subjects: Observational cosmology, Background radiations, cosmological model, background radiations, [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], 98.80.Bp, Cosmic microwave background, Particle-theory and field-theory models of the early universe, Astrophysics, 01 natural sciences, 7. Clean energy, Cosmology, observational cosmology, particle-theory and field-theory models of the early universe, Dark energy, general relativity, Elementary particle processes, neutrino: mass, Large scale structure of the universe, dark energy, 010303 astronomy & astrophysics, Mathematical Physics, media_common, Physics, COSMIC cancer database, perturbation: primordial, dark matter, elementary particle processes, large scale structure of the universe, microwave, origin and formation of the universe, radio, Astronomy and Astrophysics, Space and Planetary Science, 98.80.Es, Origin and formation of the universe, 95.36.+x, inflation: model, 98.70.Vc, Sachs-Wolfe effect, equivalence principle, non-Gaussianity, axion: thermal, 95.35.+d, axion: mass, Neutrino, signature, Astrophysics - Cosmology and Nongalactic Astrophysics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), media_common.quotation_subject, 95.85.Bh, multipole, FOS: Physical sciences, Lambda-CDM model, Astrophysics::Cosmology and Extragalactic Astrophysics, NO, polarization: rotation, power spectrum: primordial, 95.30.Cq, 0103 physical sciences, 98.80.−k, Dark matter, n: lifetime, Axion, 010308 nuclear & particles physics, 98.80.Cq, Radio, Universe, Galaxy, galaxy, 98.65.Dx, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Microwave, cosmic background radiation: anisotropy
Abstract: Based on presentations at the Fourteenth Marcel Grossmann Meeting on General Relativity, Rome, July 2015.-- et al., arXiv:1604.03819v1, Recent cosmic microwave background (CMB) data in temperature and polarization have reached high precision in estimating all the parameters that describe the current so-called standard cosmological model. Recent results about the integrated Sachs-Wolfe (ISW) effect from CMB anisotropies, galaxy surveys, and their cross-correlations are presented. Looking at fine signatures in the CMB, such as the lack of power at low multipoles, the primordial power spectrum (PPS) and the bounds on non-Gaussianities, complemented by galaxy surveys, we discuss inflationary physics and the generation of primordial perturbations in the early universe. Three important topics in particle physics, the bounds on neutrinos masses and parameters, on thermal axion mass and on the neutron lifetime derived from cosmological data are reviewed, with attention to the comparison with laboratory experiment results. Recent results from cosmic polarization rotation (CPR) analyses aimed at testing the Einstein equivalence principle (EEP) are presented. Finally, we discuss the perspectives of next radio facilities for the improvement of the analysis of future CMB spectral distortion experiments., CB, AG, ML and TT acknowledge partial support by ASI/INAF Agreement 2014-024-R.0 for the Planck LFI Activity of Phase E2.
Published: 2016

17. Recent results and perspectives on cosmology and fundamental physics from microwave surveys

Author: Agenzia Spaziale Italiana, Istituto Nazionale di Astrofisica, Burigana, C., Gruppuso, A., Liguori, Michele, Vielva, Patricio, Agenzia Spaziale Italiana, Istituto Nazionale di Astrofisica, Burigana, C., Gruppuso, A., Liguori, Michele, and Vielva, Patricio
Abstract: Recent cosmic microwave background (CMB) data in temperature and polarization have reached high precision in estimating all the parameters that describe the current so-called standard cosmological model. Recent results about the integrated Sachs-Wolfe (ISW) effect from CMB anisotropies, galaxy surveys, and their cross-correlations are presented. Looking at fine signatures in the CMB, such as the lack of power at low multipoles, the primordial power spectrum (PPS) and the bounds on non-Gaussianities, complemented by galaxy surveys, we discuss inflationary physics and the generation of primordial perturbations in the early universe. Three important topics in particle physics, the bounds on neutrinos masses and parameters, on thermal axion mass and on the neutron lifetime derived from cosmological data are reviewed, with attention to the comparison with laboratory experiment results. Recent results from cosmic polarization rotation (CPR) analyses aimed at testing the Einstein equivalence principle (EEP) are presented. Finally, we discuss the perspectives of next radio facilities for the improvement of the analysis of future CMB spectral distortion experiments.
Published: 2016

18. Moduli fields as quintessence and the chameleon

Author: Philippe Brax, Jérôme Martin, Institut de Physique Théorique - UMR CNRS 3681 (IPHT), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique de Paris (IAP), and Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: High Energy Physics - Theory, Particle physics, Physics::General Physics, Background radiations, Nuclear and High Energy Physics, FOS: Physical sciences, Cosmological constant, General Relativity and Quantum Cosmology (gr-qc), Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Cosmology, General Relativity and Quantum Cosmology, Moduli, Gravitation, Theoretical physics, High Energy Physics - Phenomenology (hep-ph), Mathematics::Algebraic Geometry, Mathematics::Symplectic Geometry, Physics, Supergravity, 98.80.Cq, Astrophysics (astro-ph), Supersymmetry, Gravitational constant, 98.70.Vc, High Energy Physics - Phenomenology, High Energy Physics - Theory (hep-th), [SDU]Sciences of the Universe [physics], Particle-theory and field-theory models of the early Universe, Quintessence
Abstract: We consider models where moduli fields are not stabilized and play the role of quintessence. In order to evade gravitational tests, we investigate the possibility that moduli behave as chameleon fields. We find that, for realistic moduli superpotentials, the chameleon effect is not strong enough, implying that moduli quintessence models are gravitationally ruled out. More generally, we state a no-go theorem for quintessence in supergravity whereby models either behave like a pure cosmological constant or violate gravitational tests, Comment: 11 pages, 1 figure
Published: 2007
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19. Inflationary cosmology in modified gravity theories

Author: Sergei D. Odintsov and Kazuharu Bamba
Subjects: High Energy Physics - Theory, modified theories of gravity, Gravity (chemistry), Cosmology and Nongalactic Astrophysics (astro-ph.CO), Physics and Astronomy (miscellaneous), General Mathematics, FOS: Physical sciences, Loop quantum gravity, Astrophysics::Cosmology and Extragalactic Astrophysics, General Relativity and Quantum Cosmology (gr-qc), General Relativity and Quantum Cosmology, Cosmology, Theoretical physics, symbols.namesake, High Energy Physics - Phenomenology (hep-ph), particle-theory and field-theory models of the early Universe, quantum geometry, spin foams, Computer Science (miscellaneous), Planck, dark energy, models beyond the standard model, Loop quantum cosmology, Inflation (cosmology), Physics, Quantum geometry, loop quantum gravity, lcsh:Mathematics, mathematical and relativistic aspects of cosmology, lcsh:QA1-939, High Energy Physics - Phenomenology, High Energy Physics - Theory (hep-th), Chemistry (miscellaneous), Dark energy, symbols, cosmology, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We review inflationary cosmology in modified gravity such as $R^2$ gravity with its extensions in order to generalize the Starobinsky inflation model. In particular, we explore inflation realized by three kinds of effects: modification of gravity, the quantum anomaly, and the $R^2$ term in loop quantum cosmology. It is explicitly demonstrated that in these inflationary models, the spectral index of scalar modes of the density perturbations and the tensor-to-scalar ratio can be consistent with the Planck results. Bounce cosmology in $F(R)$ gravity is also explained., Comment: 24 pages, no figure, invited review to appear in Symmetry
Published: 2015
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20. Cosmology with self-interacting sterile neutrinos and dark matter - A pseudoscalar model

Author: Steen Hannestad, Rasmus S. L. Hansen, Thomas Tram, and Maria Archidiacono
Subjects: Observational cosmology, Physics, Nuclear and High Energy Physics, Particle physics, Sterile neutrino, Neutrino mass and mixing, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Hot dark matter, High Energy Physics::Phenomenology, Scalar field dark matter, FOS: Physical sciences, Non-standard-model neutrinos right-handed neutrinos etc, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Cosmic neutrino background, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), 13. Climate action, Mixed dark matter, Warm dark matter, High Energy Physics::Experiment, Particle-theory and field-theory models of the early Universe, Neutrino, Light dark matter, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: Short baseline neutrino oscillation experiments have shown hints of the existence of additional sterile neutrinos in the eV mass range. Such sterile neutrinos are incompatible with cosmology because they suppress structure formation unless they can be prevented from thermalising in the early Universe or removed by subsequent decay or annihilation. Here we present a novel scenario in which both sterile neutrinos and dark matter are coupled to a new, light pseudoscalar. This can prevent thermalisation of sterile neutrinos and make dark matter sufficiently self-interacting to have an impact on galactic dynamics and possibly resolve some of the known problems with the standard cold dark matter scenario. Even more importantly it leads to a strongly self-interacting plasma of sterile neutrinos and pseudoscalars at late times and provides an excellent fit to CMB data. The usual cosmological neutrino mass problem is avoided by sterile neutrino annihilation to pseudoscalars. The preferred value of $H_0$ is substantially higher than in standard $\Lambda$CDM and in much better agreement with local measurements., Comment: 8 pages, 4 figures, matches published version
Published: 2014

21. Study of the consistency relation for single-field inflation with power spectrum oscillations

Author: Gary Shiu, Mark G. Jackson, Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Observational cosmology, High Energy Physics - Theory, Physics, Nuclear and High Energy Physics, Astrophysics - Cosmology and Extragalactic Astrophysics, Oscillation, 98.80.Cq, 98.80.Es, Strong interaction, Vacuum state, Perturbation (astronomy), Spectral density, Upper and lower bounds, [SDU]Sciences of the Universe [physics], Quantum electrodynamics, Effective field theory, Particle-theory and field-theory models of the early Universe
Abstract: International audience; We derive a theoretical upper bound on the oscillation frequency in the scalar perturbation power spectrum of single-field inflation. Oscillations are most naturally produced by modified vacua with varying phase. When this phase changes rapidly, it induces strong interactions between the scalar fluctuations. If the interactions are sufficiently strong the theory cannot be evaluated using perturbation theory, hence imposing a limit on the oscillation frequency. This complements the bound found by Weinberg governing the validity of effective field theory. The generalized consistency relation also allows one to use squeezed configurations of higher-point correlations to place constraints on the power spectrum oscillations.
Published: 2013

22. Spherically symmetric models: separating expansion from contraction in models with anisotropic pressures

Author: José P. Mimoso, Filipe C. Mena, Morgan Le Delliou, Departamento de Fı́sica, Faculdade de Ciências [University of Lisbon] (DFUL), Universidade de Lisboa (ULISBOA), Centro de Astronomia e Astrofísica da Universidade de Lisboa (CAAUL), Centro de Matemática [Minho] (CMAT), and Universidade do Minho
Subjects: space-time configurations, [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], spinor structure, FOS: Physical sciences, General Relativity and Quantum Cosmology (gr-qc), 01 natural sciences, Local equilibrium, Cosmology, General Relativity and Quantum Cosmology, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], 0103 physical sciences, 010306 general physics, Anisotropy, Contraction (operator theory), Pressure gradient, Physics, Spacetime topology, 010308 nuclear & particles physics, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], Isotropy, Mechanics, Method of undetermined coefficients, causal structure, Hydrodynamics, [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], astrophysical fluid dynamics, Particle-theory and field-theory models of the early Universe, Anisotropic fluid, cosmology
Abstract: We investigate spherically symmetric spacetimes with an anisotropic fluid and discuss the existence and stability of a dividing shell separating expanding and collapsing regions. We find that the dividing shell is defined by a relation between the pressure gradients, both isotropic and anisotropic, and the strength of the fields induced by the Misner-Sharpe mass inside the separating shell and by the pressure fluxes. This balance is a generalization of the Tolman-Oppenheimer- Volkoff equilibrium condition which defines a local equilibrium condition, but conveys also a non- local character given the definition of the Misner-Sharpe mass. We present a particular solution with dust and radiation that provides an illustration of our results., Comment: 4pp Towards New Paradigms: Proceeding Of The Spanish Relativity Meeting 2011. AIP Conference Proceedings, Volume 1458, pp. 487-490 (2012). Published in AIP Conf.Proc. 1458 (2011) 487-490
Published: 2013
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23. Periodic Cosmological Evolutions of Equation of State for Dark Energy

Author: Ujjal Debnath, Gulgasyl Nugmanova, Ratbay Myrzakulov, Kazuharu Bamba, Petr Tsyba, and Kuralay Yesmakhanova
Subjects: Chaplygin gas, media_common.quotation_subject, Dark matter, FOS: Physical sciences, General Physics and Astronomy, lcsh:Astrophysics, General Relativity and Quantum Cosmology (gr-qc), Astrophysics::Cosmology and Extragalactic Astrophysics, Type (model theory), Cosmology, General Relativity and Quantum Cosmology, particle-theory and field-theory models of the early universe, lcsh:QB460-466, dark energy, lcsh:Science, media_common, Mathematical physics, Physics, Equation of state (cosmology), cosmology, lcsh:QC1-999, Universe, Dark energy, lcsh:Q, lcsh:Physics, Quintessence
Abstract: We demonstrate two periodic or quasi-periodic generalizations of the Chaplygin gas (CG) type models to explain the origins of dark energy as well as dark matter by using the Weierstrass $\wp(t)$, $\sigma(t)$ and $\zeta(t)$ functions with two periods being infinite. If the universe can evolve periodically, a non-singular universe can be realized. Furthermore, we examine the cosmological evolution and nature of the equation of state (EoS) of dark energy in the Friedmann-Lema\^{i}tre-Robertson-Walker cosmology. It is explicitly illustrated that there exist three type models in which the universe always stays in the non-phantom (quintessence) phase, whereas it always evolves in the phantom phase, or the crossing of the phantom divide can be realized. The scalar fields and the corresponding potentials are also analyzed for different types of models., Comment: 28 pages, 6 figures, title changed, version to appear in a special issue "Modified Gravity: From Black Holes Entropy to Current Cosmology" of Entropy
Published: 2012
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24. Constraints on Cosmic Superstrings from Kaluza-Klein Emission

Author: Jean-François Dufaux, AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), APC - THEORIE, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Subjects: High Energy Physics - Theory, Physics::General Physics, Particle physics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Kaluza–Klein theory, FOS: Physical sciences, General Physics and Astronomy, General Relativity and Quantum Cosmology (gr-qc), Parameter space, String theory, 01 natural sciences, General Relativity and Quantum Cosmology, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], High Energy Physics::Theory, High Energy Physics - Phenomenology (hep-ph), Big Bang nucleosynthesis, 0103 physical sciences, 010306 general physics, Physics, COSMIC cancer database, String and brane phenomenology, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], 010308 nuclear & particles physics, Gravitational wave, Superstring theory, Extended classical solutions, Cosmic string, High Energy Physics - Phenomenology, High Energy Physics - Theory (hep-th), [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], Particle-theory and field-theory models of the early Universe, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], cosmic strings domain walls texture, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: Cosmic super-strings interact generically with a tower of light and/or strongly coupled Kaluza-Klein (KK) modes associated with the geometry of the internal space. We study the production of KK particles by cosmic super-string loops, and show that it is constrained by Big Bang Nucleosynthesis. We study the resulting constraints in the parameter space of the underlying string theory model and highlight their complementarity with the regions that can be probed by current and upcoming gravitational wave experiments., Comment: v3: misprints corrected and refs. added, to appear in PRL
Published: 2012

25. Stochastic background from cosmic (super)strings: Popcorn-like and (Gaussian) continuous regimes

Author: S. Giampanis, Vuk Mandic, Xavier Siemens, Tania Regimbau, Astrophysique Relativiste Théories Expériences Métrologie Instrumentation Signaux (ARTEMIS), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, and Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Nuclear and High Energy Physics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, General Relativity and Quantum Cosmology (gr-qc), Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Wave generation and sources, Parameter space, 01 natural sciences, String (physics), General Relativity and Quantum Cosmology, Pulsar, 0103 physical sciences, Strings and branes, 010306 general physics, Physics, COSMIC cancer database, Einstein Telescope, 010308 nuclear & particles physics, Gravitational wave, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Extended classical solutions, LIGO, Cosmic string, Particle-theory and field-theory models of the early Universe, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], cosmic strings domain walls texture, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: In the era of the next generation of gravitational wave experiments a stochastic background from cusps of cosmic (super)strings is expected to be probed and, if not detected, to be significantly constrained. A popcorn-like background can be, for part of the parameter space, as pronounced as the (Gaussian) continuous contribution from unresolved sources that overlap in frequency and time. We study both contributions from unresolved cosmic string cusps over a range of frequencies relevant to ground based interferometers, such as LIGO/Virgo second generation (AdLV) and Einstein Telescope (ET) third generation detectors, the space antenna LISA and Pulsar Timing Arrays (PTA). We compute the sensitivity (at $2 \sigma$ level) in the parameter space for AdLV, ET, LISA and PTA. We conclude that the popcorn regime is complementary to the continuous background. Its detection could therefore enhance confidence in a stochastic background detection and possibly help determine fundamental string parameters such as the string tension and the reconnection probability., Comment: 21 pages, 11 figures ; revised version after correction of a typo in eq. 4.1
Published: 2012

26. Radio Broadcasts from Superconducting Strings

Author: Daniele A. Steer, Eray Sabancilar, Yi-Fu Cai, Tanmay Vachaspati, APC - THEORIE, AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Subjects: High Energy Physics - Theory, Nuclear and High Energy Physics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), microwave, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, Submillimeter, 010303 astronomy & astrophysics, Computer Science::Databases, Physics, Superconductivity, Coupling constant, domain walls, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], 010308 nuclear & particles physics, Texture (cosmology), Extended classical solutions, cosmic strings, Radio, Cosmic string, High Energy Physics - Phenomenology, High Energy Physics - Theory (hep-th), [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Particle-theory and field-theory models of the early Universe, Radio frequency, Transient (oscillation), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], texture, Event (particle physics), Microwave, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: Superconducting cosmic strings can give transient electromagnetic signatures that we argue are most evident at radio frequencies. We investigate the three different kinds of radio bursts from cusps, kinks, and kink-kink collisions on superconducting strings. We find that the event rate is dominated by kink bursts in a range of parameters that are of observational interest, and can be quite high (several a day at 1 Jy flux) for a canonical set of parameters. In the absence of events, the search for radio transients can place stringent constraints on superconducting cosmic strings., Comment: 11 pages, 3 figures
Published: 2012
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27. Primordial Non-Gaussianities of Gravitational Waves in the Most General Single-Field Inflation Model with Second-Order Field Equations

Author: Tsutomu Kobayashi, Masahide Yamaguchi, Xian Gao, Jun'ichi Yokoyama, Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire de Physique Théorique de l'ENS [École Normale Supérieure] (LPTENS), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Kyoto University, Tokyo Institute of Technology [Tokyo] (TITECH), Research Center for the Early Universe (RESCEU), The University of Tokyo (UTokyo), and ANR-09-BLAN-0157,STR-COSMO,Cosmologie des cordes(2009)
Subjects: High Energy Physics - Theory, Cosmic microwave background, Cosmic background radiation, General Physics and Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, General Relativity and Quantum Cosmology, Gravitation, symbols.namesake, Born–Infeld model, Non-Gaussianity, Quantum mechanics, 0103 physical sciences, 010306 general physics, Mathematical physics, Physics, 010308 nuclear & particles physics, Gravitational wave, Graviton, Gravitational-wave astrophysics, High Energy Physics - Phenomenology, Einstein tensor, [SDU]Sciences of the Universe [physics], symbols, Particle-theory and field-theory models of the early Universe
Abstract: International audience; We completely clarify the feature of primordial non-Gaussianities of tensor perturbations in the most general single-field inflation model with second-order field equations. It is shown that the most general cubic action for the tensor perturbation hij is composed only of two contributions, one with two spacial derivatives and the other with one time derivative on each hij. The former is essentially identical to the cubic term that appears in Einstein gravity and predicts a squeezed shape, while the latter newly appears in the presence of the kinetic coupling to the Einstein tensor and predicts an equilateral shape. Thus, only two shapes appear in the graviton bispectrum of the most general single-field inflation model, which could open a new clue to the identification of inflationary gravitational waves in observations of cosmic microwave background anisotropies as well as direct detection experiments.
Published: 2011

28. Search for cosmic strings in the COSMOS survey

Author: Jodi L. Christiansen, George F. Smoot, J. Goldman, M. Foley, E. Albin, T. Fletcher, I. P.W. Teng, APC - Cosmologie, AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Physique Corpusculaire et Cosmologie - Collège de France (PCC), Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)
Subjects: Physics, Nuclear and High Energy Physics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), 010308 nuclear & particles physics, [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Cosmic microwave background, Astronomy, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Omega, Advanced Camera for Surveys, Galaxy, Redshift, Cosmic string, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Gravitational lens, Observational cosmology, 0103 physical sciences, Particle-theory and field-theory models of the early Universe, 010306 general physics, Astrophysics::Galaxy Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We search the COSMOS survey for pairs of galaxies consistent with the gravitational lensing signature of a cosmic string. The COSMOS survey imaged 1.64 square degrees using the Advanced Camera for Surveys aboard the Hubble Space Telescope. Our technique includes estimates of the efficiency for finding the lensed galaxy pair. We find no evidence for cosmic strings with a mass per unit length of $G\ensuremath{\mu}/{c}^{2}l3.0\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}7}$ out to redshifts greater than 0.6 and set 95% upper limits. This corresponds to a global 95% upper limit of ${\ensuremath{\Omega}}_{\mathrm{strings}}l0.0028$.
Published: 2011

29. Constraints on the fundamental string coupling from B-mode experiments

Author: Anastasios Avgoustidis, Adam Moss, Levon Pogosian, Edmund J. Copeland, Daniele A. Steer, Alkistis Pourtsidou, APC - THEORIE, AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut für theoretische Physik, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut für theoretische Physik
Subjects: High Energy Physics - Theory, Observational cosmology, Particle physics, Background radiations, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Cosmic microwave background, FOS: Physical sciences, General Physics and Astronomy, General Relativity and Quantum Cosmology (gr-qc), String theory, 01 natural sciences, General Relativity and Quantum Cosmology, Quantum mechanics, 0103 physical sciences, 010306 general physics, Scaling, Coupling constant, Physics, String and brane phenomenology, 010308 nuclear & particles physics, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], Superstring theory, Observable, Polarization (waves), High Energy Physics - Theory (hep-th), [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], Particle-theory and field-theory models of the early Universe, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We study signatures of cosmic superstring networks containing strings of multiple tensions and Y-junctions, on the cosmic microwave background (CMB) temperature and polarisation spectra. Focusing on the crucial role of the string coupling constant $g_s$, we show that the number density and energy density of the scaling network are dominated by different types of string in the $g_s \sim 1$ and $g_s \ll 1$ limits. This can lead to an observable shift in the position of the B-mode peak --- a distinct signal leading to a direct constraint on $g_s$. We forecast the joint bounds on $g_s$ and the fundamental string tension $\mu_F$ from upcoming and future CMB polarisation experiments, as well as the signal to noise in detecting the difference between B-mode signals in the limiting cases of large and small $g_s$. We show that such a detectable shift is within reach of planned experiments., Comment: 4 pages, 4 figures; v2: matches version published in PRL
Published: 2011

30. Light from cosmic strings

Author: Daniele A. Steer, Tanmay Vachaspati, APC - THEORIE, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut für theoretische Physik, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik
Subjects: High Energy Physics - Theory, Nuclear and High Energy Physics, Photon, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Electromagnetic spectrum, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Radiation, 01 natural sciences, String (physics), Electromagnetic radiation, High Energy Physics::Theory, 0103 physical sciences, 010306 general physics, Nonlinear Sciences::Pattern Formation and Solitons, Physics, 010308 nuclear & particles physics, Gravitational wave, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], Cosmic string, Massless particle, High Energy Physics - Theory (hep-th), Particle-theory and field-theory models of the early Universe, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: The time-dependent metric of a cosmic string leads to an effective interaction between the string and photons - the "gravitational Aharonov-Bohm" effect -- and causes cosmic strings to emit light. We evaluate the radiation of pairs of photons from cosmic strings and find that the emission from cusps, kinks and kink-kink collisions occurs with a flat spectrum at all frequencies up to the string scale. Further, cusps emit a beam of photons, kinks emit along a curve, and the emission at a kink-kink collision is in all directions. The emission of light from cosmic strings could provide an important new observational signature of cosmic strings that is within reach of current experiments for a range of string tensions., Comment: 8 pages, 1 figure
Published: 2011

31. Quantum properties of a non-Gaussian state in the large-N approximation

Author: Florian Gautier, J. Serreau, APC - THEORIE, AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut für theoretische Physik, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik
Subjects: Density matrix, High Energy Physics - Theory, Nuclear and High Energy Physics, Quantum decoherence, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Nuclear Theory, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], quantum statistical methods, Gaussian, FOS: Physical sciences, 01 natural sciences, Gaussian random field, Nuclear Theory (nucl-th), symbols.namesake, Theory of quantized fields, High Energy Physics - Phenomenology (hep-ph), [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Quantum mechanics, 0103 physical sciences, Gaussian function, 010306 general physics, Finite-temperature field theory, Physics, Quantum discord, Quantum Physics, 010308 nuclear & particles physics, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], Decoherence, Quantum relative entropy, High Energy Physics - Phenomenology, High Energy Physics - Theory (hep-th), [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], symbols, open systems, Particle-theory and field-theory models of the early Universe, Quantum Physics (quant-ph), Joint quantum entropy, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We study the properties of a non-Gaussian density matrix for a O(N) scalar field in the context of the incomplete description picture. This is of relevance for studies of decoherence and entropy production in quantum field theory. In particular, we study how the inclusion of the simplest non-Gaussian correlator in the set of measured observables modifies the effective (Gaussian) description one can infer from the knowledge of the two-point functions only. We compute exactly the matrix elements of the non-Gaussian density matrix at leading order in a 1/N-expansion. This allows us to study the quantum properties (purity, entropy, coherence) of the corresponding state for arbitrarily strong nongaussianity. We find that if the Gaussian and the non-Gaussian observers essentially agree concerning quantum purity or correlation entropy, their conclusion can significantly differ for other, more detailed aspects such as the degree of quantum coherence of the system., Comment: 14 pages, 7 figures. Published version (Phys. Rev. D, minor corrections)
Published: 2011
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32. Proliferation of sharp kinks on cosmic (super)string loops with junctions

Author: A Bohe, Thomas Hertog, Pierre Binétruy, D. A Steer, APC - THEORIE, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik, Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut für theoretische Physik, and Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)
Subjects: High Energy Physics - Theory, Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Gravitational wave, Texture (cosmology), domain walls, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], FOS: Physical sciences, Extended classical solutions, Space (mathematics), 01 natural sciences, String (physics), cosmic strings, Cosmic string, Amplitude, Classical mechanics, High Energy Physics - Theory (hep-th), Orders of magnitude (time), 0103 physical sciences, Configuration space, Particle-theory and field-theory models of the early Universe, 010306 general physics, Nonlinear Sciences::Pattern Formation and Solitons, texture
Abstract: Motivated by their effect on the gravitational wave signal emitted by cosmic strings, we study the dynamics of kinks on strings of different tensions meeting at junctions. The propagation of a kink through a Y-junction leads to the formation of three `daughter' kinks. Assuming a uniform distribution of the incoming wave vectors at the junction, we find there is a significant region of configuration space in which the sharpness of at least one of the daughter kinks is enhanced relative to the sharpness of the initial kink. For closed loops with junctions we show this leads to an exponential growth in time of very sharp kinks. Using numerical simulations of realistic, evolving cosmic string loops with junctions to calculate the distribution of kink amplitudes as a function of time, we show that loops of this kind typically develop several orders of magnitude of very sharp kinks before the two junctions collide. This collision, or other effects such as gravitational backreaction, may end the proliferation., Comment: 27 pages, 14 figures
Published: 2010

33. No-boundary measure in the regime of eternal inflation

Author: Thomas Hertog, James B. Hartle, Stephen W. Hawking, Department of Applied Mathematics and Theoretical Physics (DAMTP), University of Cambridge [UK] (CAM), APC - THEORIE, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), Department of Applied Mathematics and Theoretical Physics / Centre for Mathematical Sciences (DAMTP/CMS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik, Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut für theoretische Physik
Subjects: High Energy Physics - Theory, Nuclear and High Energy Physics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], media_common.quotation_subject, FOS: Physical sciences, Observable universe, General Relativity and Quantum Cosmology (gr-qc), 01 natural sciences, Cosmology, General Relativity and Quantum Cosmology, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Quantum cosmology, Non-Gaussianity, 0103 physical sciences, Statistical physics, 010306 general physics, Eternal inflation, media_common, Inflation (cosmology), Physics, 010308 nuclear & particles physics, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], Quantum gravity, Universe, Classical mechanics, High Energy Physics - Theory (hep-th), [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], Origin and formation of the Universe, Particle-theory and field-theory models of the early Universe, Scalar field, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: The no-boundary wave function (NBWF) specifies a measure for prediction in cosmology that selects inflationary histories and remains well behaved for spatially large or infinite universes. This paper explores the predictions of the NBWF for linear scalar fluctuations about homogeneous and isotropic backgrounds in models with a single scalar field moving in a quadratic potential. We treat both the space-time geometry of the universe and the observers inhabiting it quantum mechanically. We evaluate top-down probabilities for local observations that are conditioned on the NBWF and on part of our data as observers of the universe. For models where the most probable histories do not have a regime of eternal inflation, the NBWF predicts homogeneity on large scales, a specific non-Gaussian spectrum of observable fluctuations, and a small amount of inflation in our past. By contrast, for models where the dominant histories have a regime of eternal inflation, the NBWF predicts significant inhomogeneity on scales much larger than the present horizon, a Gaussian spectrum of observable fluctuations, and a long period of inflation in our past. The absence or presence of local non-Gaussianity therefore provides information about the global structure of the universe, assuming the NBWF., 29 pages, 8 figures
Published: 2010

34. Cosmological Simulations on a Grid of Computers

Author: Benjamin Depardon, Eddy Caron, Frédéric Desprez, Jérémy Blaizot, Hélène Courtois, Jean-Michel Alimi, André Fuözfa, Laboratoire de l'Informatique du Parallélisme (LIP), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS), Algorithms and Scheduling for Distributed Heterogeneous Platforms (GRAAL), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire de l'Informatique du Parallélisme (LIP), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Cosmologie Observationnelle, Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre de Recherche Astrophysique de Lyon (CRAL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Inria, Grid'5000, ANR-05-CIGC-0011,LEGO,League for Efficient Grid Operations(2005), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'Informatique du Parallélisme ( LIP ), École normale supérieure - Lyon ( ENS Lyon ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique ( Inria ) -Centre National de la Recherche Scientifique ( CNRS ), Algorithms and Scheduling for Distributed Heterogeneous Platforms ( GRAAL ), Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut National de Recherche en Informatique et en Automatique ( Inria ) -Laboratoire de l'Informatique du Parallélisme ( LIP ), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique ( Inria ) -Centre National de la Recherche Scientifique ( CNRS ) -École normale supérieure - Lyon ( ENS Lyon ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique ( CNRS ), Institut de Physique Nucléaire de Lyon ( IPNL ), Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ), Centre de Recherche Astrophysique de Lyon ( CRAL ), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), and ANR-05-CIGC-0011,LEGO,League for Efficient Grid Operations ( 2005 )
Subjects: FOS: Computer and information sciences, Parallel computing, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Computer science, [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Computation, Distributed computing, FOS: Physical sciences, Grid-RPC, 02 engineering and technology, Sky surveys, 01 natural sciences, Execution time, Scheduling (computing), [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Databases, [ INFO.INFO-DC ] Computer Science [cs]/Distributed, Parallel, and Cluster Computing [cs.DC], Data acquisition, Universe, 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, N-body simulations, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Local uni- verse, Middleware, 020203 distributed computing, Grid middleware, Archives, Atlases, Astronomical catalogues, Grid, Cosmology, Astronomical catalogs, Retrieval systems, Computer Science - Distributed, Parallel, and Cluster Computing, Distributed, Parallel, and Cluster Computing (cs.DC), Origin and formation of the Universe, Particle-theory and field-theory models of the early Universe, [INFO.INFO-DC]Computer Science [cs]/Distributed, Parallel, and Cluster Computing [cs.DC], Astrophysics - Instrumentation and Methods for Astrophysics, Data acquisition: hardware and software, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: The work presented in this paper aims at restricting the input parameter values of the semi-analytical model used in GALICS and MOMAF, so as to derive which parameters influence the most the results, e.g., star formation, feedback and halo recycling efficiencies, etc. Our approach is to proceed empirically: we run lots of simulations and derive the correct ranges of values. The computation time needed is so large, that we need to run on a grid of computers. Hence, we model GALICS and MOMAF execution time and output files size, and run the simulation using a grid middleware: DIET. All the complexity of accessing resources, scheduling simulations and managing data is harnessed by DIET and hidden behind a web portal accessible to the users., Accepted and Published in AIP Conference Proceedings 1241, 2010, pages 816-825
Published: 2010

35. Local Observation in Eternal inflation

Author: James B. Hartle, Thomas Hertog, Stephen W. Hawking, Department of Applied Mathematics and Theoretical Physics (DAMTP), University of Cambridge [UK] (CAM), APC - THEORIE, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut für theoretische Physik, Department of Applied Mathematics and Theoretical Physics / Centre for Mathematical Sciences (DAMTP/CMS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik
Subjects: High Energy Physics - Theory, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Primordial fluctuations, [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], media_common.quotation_subject, General Physics and Astronomy, FOS: Physical sciences, General Relativity and Quantum Cosmology (gr-qc), 01 natural sciences, Particle horizon, General Relativity and Quantum Cosmology, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], De Sitter universe, Light cone, 0103 physical sciences, Statistical physics, 010306 general physics, Eternal inflation, media_common, Inflation (cosmology), Physics, 010308 nuclear & particles physics, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], Quantum gravity, Quantum cosmology, Universe, Classical mechanics, High Energy Physics - Theory (hep-th), [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], Inflationary epoch, Origin and formation of the Universe, Particle-theory and field-theory models of the early Universe, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We consider landscape models that admit several regions where the conditions for eternal inflation hold. It is shown that one can use the no-boundary wave function to calculate small departures from homogeneity within our past light cone despite the possibility of much larger fluctuations on super horizon scales. The dominant contribution comes from the history exiting eternal inflation at the lowest value of the potential. In a class of landscape models this predicts a tensor to scalar ratio of about 10%. In this way the no-boundary wave function defines a measure for the prediction of local cosmological observations., Comment: 4 pages; v2: published version
Published: 2010
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36. Relative information entropy of an inhomogeneous universe

Author: Masaaki Morita, Thomas Buchert, Akio Hosoya, Nan Li, Jean-Michel Alimi, André Fuözfa, Department of Material Science and Technology, Nagaoka University of Technology, GALPAC Théorie, Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Tokyo Institute of Technology [Tokyo] (TITECH), Université Catholique de Louvain = Catholic University of Louvain (UCL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Observational cosmology, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Linear perturbation theory, FOS: Physical sciences, General Relativity and Quantum Cosmology (gr-qc), 01 natural sciences, General Relativity and Quantum Cosmology, Gravitation, symbols.namesake, Universe, 98.80.Jk, 95.30.Sf, 89.70.Cf, 98.65.Dx, Friedmann–Lemaître–Robertson–Walker metric, 0103 physical sciences, Entropy (information theory), Phase transitions: general studies, Statistical physics, 010306 general physics, Integral equations, Physics, Conjecture, 010308 nuclear & particles physics, Time evolution, Cosmological model, Nonlinear system, [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], symbols, Particle-theory and field-theory models of the early Universe, entropy, cosmology, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: In the context of averaging an inhomogeneous cosmological model, we propose a natural measure identical to the Kullback-Leibler relative information entropy, which expresses the distinguishability of the local inhomogeneous density field from its spatial average on arbitrary compact domains. This measure is expected to be an increasing function in time and thus to play a significant role in studying gravitational entropy. To verify this conjecture, we explore the time evolution of the measure using the linear perturbation theory of a spatially flat FLRW model and a spherically symmetric nonlinear solution. We discuss the generality and conditions for the time-increasing nature of the measure, and also the connection to the backreaction effect caused by inhomogeneities., Comment: 9 pages, 4 figures, LaTeX 2e using aipproc.cls, published in AIP Conf. Proc., minor corrections made
Published: 2010

37. Multitrace deformation of the Aharony-Bergman-Jafferis-Maldacena theory

Author: Neil Turok, Thomas Hertog, Ben Craps, Solvay Brussels School of Economics and Management [Brussels] (ULB), Université libre de Bruxelles (ULB), APC - THEORIE, AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), International Solvay Institutes, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik, Theoretical Physics, Physics, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut für theoretische Physik
Subjects: Physics, Nuclear and High Energy Physics, AdS/CFT correspondence, 010308 nuclear & particles physics, Big Crunch, [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], Supergravity, Order (ring theory), 01 natural sciences, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Quantum mechanics, 0103 physical sciences, Beta function (physics), Compactification and four-dimensional models, Anti-de Sitter space, Particle-theory and field-theory models of the early Universe, 010306 general physics, Ultraviolet fixed point, Orbifold, Mathematical physics
Abstract: Motivated by the study of big crunch singularities in asymptotically ${\mathrm{AdS}}_{4}$ space-times, we consider a marginal triple trace deformation of Aharony-Bergman-Jafferis-Maldacena (ABJM) theory. The deformation corresponds to adding a potential which is unbounded below. In a 't Hooft large $N$ limit, the beta function for the triple trace deformation vanishes, which is consistent with the near-boundary behavior of the bulk fields. At the next order in the $1/N$ expansion, the triple trace couplings exhibit nontrivial running, which we analyze explicitly in the limit of zero 't Hooft coupling, in which the model reduces to an $O(N)\ifmmode\times\else\texttimes\fi{}O(N)$ vector model with large $N$. In this limit, we establish the existence of a perturbative UV fixed point, and we comment on possible nonperturbative effects. We also show that the bulk analysis leading to big crunch singularities extends to the ${\mathbb{Z}}_{k}$ orbifold models dual to ABJM theory.
Published: 2009

38. New constraints on variations of the fine structure constant from CMB anisotropies

Author: Silvia Galli, Alessandro Melchiorri, Carlos Martins, Eloisa Menegoni, James G. Bartlett, Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome], APC - Cosmologie, AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Department of Applied Mathematics and Theoretical Physics (DAMTP), University of Cambridge [UK] (CAM), Università degli Studi di Roma 'La Sapienza' [Rome], Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Physique Corpusculaire et Cosmologie - Collège de France (PCC), Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF)-Centre National de la Recherche Scientifique (CNRS), Department of Applied Mathematics and Theoretical Physics / Centre for Mathematical Sciences (DAMTP/CMS), Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] (UNIROMA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Nuclear and High Energy Physics, Background radiations, Cosmology and Nongalactic Astrophysics (astro-ph.CO), [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Cosmic microwave background, FOS: Physical sciences, General Relativity and Quantum Cosmology (gr-qc), Astrophysics, 01 natural sciences, General Relativity and Quantum Cosmology, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], symbols.namesake, High Energy Physics - Phenomenology (hep-ph), Hubble space telescope, 0103 physical sciences, Anisotropy, 010303 astronomy & astrophysics, Physics, 010308 nuclear & particles physics, Fine-structure constant, Polarization (waves), Astrophysics - Astrophysics of Galaxies, CMB cold spot, High Energy Physics - Phenomenology, 13. Climate action, Astrophysics of Galaxies (astro-ph.GA), symbols, Particle-theory and field-theory models of the early Universe, Determination of fundamental constants, Astrophysics - Cosmology and Nongalactic Astrophysics, Hubble's law
Abstract: We demonstrate that recent measurements of Cosmic Microwave Background temperature and polarization anisotropy made by the ACBAR, QUAD and BICEP experiments substantially improve the cosmological constraints on possible variations of the fine structure constant in the early universe. This data, combined with the five year observations from the WMAP mission yield the constraint alpha/alpha_0 = 0.987 \pm 0.012 at 68% c.l.. The inclusion of the new HST constraints on the Hubble constant further increases the accuracy to alpha/alpha_0 = 1.001 \pm 0.007 at 68% c.l., bringing possible deviations from the current value below the 1% level and improving previous constraints by a factor 3., Comment: 3 pages, 2 figures
Published: 2009

39. Replication regulates volume weighting in quantum cosmology

Author: Thomas Hertog, James B. Hartle, APC - THEORIE, AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut für theoretische Physik, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut für theoretische Physik
Subjects: High Energy Physics - Theory, Nuclear and High Energy Physics, [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], media_common.quotation_subject, FOS: Physical sciences, General Relativity and Quantum Cosmology (gr-qc), 01 natural sciences, General Relativity and Quantum Cosmology, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Quantum cosmology, Quantum state, Minisuperspace, 0103 physical sciences, Statistical physics, 010306 general physics, media_common, Physics, 010308 nuclear & particles physics, Quantum gravity, Universe, Weighting, Classical mechanics, High Energy Physics - Theory (hep-th), Regularization (physics), Origin and formation of the Universe, Particle-theory and field-theory models of the early Universe, Scalar field
Abstract: Probabilities for observations in cosmology are conditioned both on the universe's quantum state and on local data specifying the observational situation. We show the quantum state defines a measure for prediction through such conditional probabilities that is well behaved for spatially large or infinite universes when the probabilities that our data is replicated are taken into account. In histories where our data are rare volume weighting connects top-down probabilities conditioned on both the data and the quantum state to the bottom-up probabilities conditioned on the quantum state alone. We apply these principles to a calculation of the number of inflationary e-folds in a homogeneous, isotropic minisuperspace model with a single scalar field moving in a quadratic potential. We find that volume weighting is justified and the top-down probabilities favor a large number of e-folds., 13 pages, 3 figures; v2: correction case of data on multiple surfaces, clarification objectivity
Published: 2009

40. Gravitational Wave Bursts from Cosmic Superstrings with Y-junctions

Author: Pierre Binétruy, D. A Steer, A Bohe, Thomas Hertog, APC - THEORIE, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut für theoretische Physik, Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik
Subjects: Physics, High Energy Physics - Theory, Nuclear and High Energy Physics, COSMIC cancer database, 010308 nuclear & particles physics, Gravitational wave, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], Superstring theory, FOS: Physical sciences, Astrophysics, Wave generation and sources, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, 01 natural sciences, Signal, Cosmic string, High Energy Physics::Theory, High Energy Physics - Theory (hep-th), Condensed Matter::Superconductivity, 0103 physical sciences, Speed of light, Particle-theory and field-theory models of the early Universe, 010306 general physics
Abstract: Cosmic superstring loops generically contain strings of different tensions that meet at Y-junctions. These loops evolve non-periodically in time, and have cusps and kinks that interact with the junctions. We study the effect of junctions on the gravitational wave signal emanating from cosmic string cusps and kinks. We find that earlier results on the strength of individual bursts from cusps and kinks on strings without junctions remain largely unchanged, but junctions give rise to additional contributions to the gravitational wave signal coming from strings expanding at the speed of light at a junction and kinks passing through a junction., 20 pages, 5 figures
Published: 2009

41. Dynamical D4-D8 and D3-D7 branes in supergravity

Author: Misao Sasaki, Pierre Binétruy, Kunihito Uzawa, APC - THEORIE, AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut für theoretische Physik, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut für theoretische Physik
Subjects: High Energy Physics - Theory, Nuclear and High Energy Physics, Particle physics, FOS: Physical sciences, General Relativity and Quantum Cosmology (gr-qc), 01 natural sciences, General Relativity and Quantum Cosmology, 0103 physical sciences, Brane cosmology, 11.25.−w, 11.27.+d, 98.80.Cq, Strings and branes, 010306 general physics, Mathematical physics, Physics, Compactification (physics), Spacetime, 010308 nuclear & particles physics, domain walls, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], Supergravity, Space time, Extended classical solutions, cosmic strings, High Energy Physics - Theory (hep-th), [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], Dilaton, Anti-de Sitter space, Particle-theory and field-theory models of the early Universe, Brane, texture
Abstract: We present a class of dynamical solutions for intersecting D4-D8 and D3-D7 brane systems in ten-dimensional type IIA and IIB supergravity. We discuss if these solutions can be recovered in lower-dimensional effective theories for the warped compactification of a general p-brane system. It is found that an effective $p+1$-dimensional description is not possible in general due to the entanglement of the transverse coordinates and the $p+1$-dimensional coordinates in the metric components. For the D4-D8 brane system, the dynamical solutions reduces to a static warped ${\rm AdS_6}\times {\rm S}^4$ geometry in a certain spacetime region. For the D3-D7 brane system, we find a dynamical solution whose metric form is similar to that of a D3-brane solution. The main difference is the existence of a nontrivial dilaton configuration in the D3-D7 solution. Then we discuss cosmology of these solutions. We find that they behave like a Kasner-type cosmological solution at $\tau\to\infty$, while it reduces to a warped static solution at $\tau\to0$, where $\tau$ is the cosmic time., Comment: 25 pages, no figure, typos corrected, references and discussions of D3-D7 brane solutions added
Published: 2009

42. Delayed Recombination and Standard Rulers

Author: Francesco De Bernardis, Silvia Galli, Joseph Silk, Alessandro Melchiorri, Rachel Bean, Licia Verde, APC - Cosmologie, AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Physique Corpusculaire et Cosmologie - Collège de France (PCC), Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)
Subjects: Nuclear and High Energy Physics, [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Cosmic microwave background, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], 0103 physical sciences, 010303 astronomy & astrophysics, Physics, COSMIC cancer database, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Oscillation, 98.80.Cq, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, Galaxy, Baryon, 13. Climate action, Dark energy, Baryon acoustic oscillations, Particle-theory and field-theory models of the early Universe, Recombination
Abstract: Measurements of Baryonic Acoustic Oscillations in galaxy surveys have been recognized as a powerful tool for constraining dark energy. However, this method relies on the knowledge of the size of the acoustic horizon at recombination derived from Cosmic Microwave Background Anisotropy measurements. This estimate is typically derived assuming a standard recombination scheme; additional radiation sources can delay recombination altering the cosmic ionization history and the cosmological inferences drawn from CMB and BAO data. In this paper we quantify the effect of delayed recombination on the determination of dark energy parameters from future BAO surveys such as BOSS and WFMOS. We find the impact to be small but still not negligible. In particular, if recombination is non-standard (to a level still allowed by CMB data), but this is ignored, future surveys may incorrectly suggest the presence of a redshift dependent dark energy component. On the other hand, in the case of delayed recombination, adding to the analysis one extra parameter describing deviations from standard recombination, does not significantly degrade the error-bars on dark energy parameters and yields unbiased estimates., 8 pages, 5 figures
Published: 2009

43. Composite dark matter from a model with composite Higgs boson

Author: Chris Kouvaris, Maxim Yu. Khlopov, APC - THEORIE, AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut für theoretische Physik, Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut für theoretische Physik
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Astrophysics (astro-ph), Dark matter, Scalar field dark matter, FOS: Physical sciences, Technicolor, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Technicolor models, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Baryon asymmetry, astro-ph, Weakly interacting massive particles, 0103 physical sciences, Higgs boson, Warm dark matter, Particle-theory and field-theory models of the early Universe, 010306 general physics, Light dark matter
Abstract: In a previous paper \cite{Khlopov:2007ic}, we showed how the minimal walking technicolor model (WTC) can provide a composite dark matter candidate, by forming bound states between a -2 electrically charged techniparticle and a $^4He^{++}$. We studied the properties of these \emph{techni-O-helium} $tOHe$ "atoms", which behave as warmer dark matter rather than cold. In this paper we extend our work on several different aspects. We study the possibility of a mixed scenario where both $tOHe$ and bound states between +2 and -2 electrically charged techniparticles coexist in the dark matter density. We argue that these newly proposed bound states solely made of techniparticles, although they behave as Weakly Interacting Massive Particles (WIMPs), due to their large elastic cross section with nuclei, can only account for a small percentage of the dark matter density. Therefore we conclude that within the minimal WTC, composite dark matter should be mostly composed of $tOHe$. Moreover in this paper, we put cosmological bounds in the masses of the techniparticles, if they compose the dark matter density. Finally we propose within this setup, a possible explanation of the discrepancy between the DAMA/NaI and DAMA/LIBRA findings and the negative results of CDMS and other direct dark matter searches that imply nuclear recoil measurement, which should accompany ionization., 23 pages
Published: 2008

44. Statistical mechanics of strings with Y-junctions

Author: Daniele A. Steer, Ray J. Rivers, APC - THEORIE, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik, Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut für theoretische Physik
Subjects: High Energy Physics - Theory, Nuclear and High Energy Physics, [PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Critical phenomena, FOS: Physical sciences, 01 natural sciences, String (physics), Theoretical physics, High Energy Physics::Theory, Quantum mechanics, 0103 physical sciences, 010306 general physics, Phase diagram, Physics, 010308 nuclear & particles physics, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], 98.80.Cq, [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Superstring theory, Statistical mechanics, Fermion, Partition function (mathematics), Mean field theory, High Energy Physics - Theory (hep-th), Particle-theory and field-theory models of the early Universe, Particle Physics - Theory
Abstract: We investigate the Hagedorn transitions of string networks with Y-junctions as may occur, for example, with $(p,q)$ cosmic superstrings. In a simplified model with three different types of string, the partition function reduces to three generalized coupled XY models. We calculate the phase diagram and show that, as the system is heated, the lightest strings first undergo the Hagedorn transition despite the junctions. There is then a second, higher, critical temperature above which infinite strings of all tensions, and junctions, exist. Conversely, on cooling to low temperatures, only the lightest strings remain, but they collapse into small loops.
Published: 2008
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45. Dark Energy and the MSSM

Author: Philippe Brax, Jerome Martin, Institut de Physique Théorique - UMR CNRS 3681 (IPHT), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique de Paris (IAP), and Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: High Energy Physics - Theory, Background radiations, Nuclear and High Energy Physics, Particle physics, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, General Relativity and Quantum Cosmology (gr-qc), Astrophysics, General Relativity and Quantum Cosmology, Standard Model, symbols.namesake, High Energy Physics - Phenomenology (hep-ph), Physics, 98.80.Cq, High Energy Physics::Phenomenology, Astrophysics (astro-ph), Supersymmetry, Supersymmetry breaking, 98.70.Vc, High Energy Physics - Phenomenology, High Energy Physics - Theory (hep-th), [SDU]Sciences of the Universe [physics], Higgs boson, symbols, Dark energy, Particle-theory and field-theory models of the early Universe, Higgs mechanism, Quintessence, Minimal Supersymmetric Standard Model
Abstract: We consider the coupling of quintessence to observable matter in supergravity and study the dynamics of both supersymmetry breaking and quintessence in this context. We investigate how the quintessence potential is modified by supersymmetry breaking and analyse the structure of the soft supersymmetry breaking terms. We pay attention to their dependence on the quintessence field and to the electroweak symmetry breaking, ie the pattern of fermion masses at low energy within the Minimal Supersymmetric Standard Model (MSSM) coupled to quintessence. In particular, we compute explicitly how the fermion masses generated through the Higgs mechanism depend on the quintessence field for a general model of quintessence. Fifth force and equivalence principle violations are potentially present as the vacuum expectation values of the Higgs bosons become quintessence field dependent. We emphasize that equivalence principle violations are a generic consequence of the fact that, in the MSSM, the fermions couple differently to the two Higgs doublets. Finally, we also discuss how the scaling of the cold dark and baryonic matter energy density is modified and comment on the possible variation of the gauge coupling constants, among which is the fine structure constant, and of the proton-electron mass ratio, Comment: 26 pages, minor corrections, typos corrected
Published: 2006
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46. Vacuum stability in the early universe and the backreaction of classical gravity.

Author: Markkanen T
Abstract: In the case of a metastable electroweak vacuum, the quantum corrected effective potential plays a crucial role in the potential instability of the standard model. In the early universe, in particular during inflation and reheating, this instability can be triggered leading to catastrophic vacuum decay. We discuss how the large space-time curvature of the early universe can be incorporated in the calculation and in many cases significantly modify the flat space prediction. The two key new elements are the unavoidable generation of the non-minimal coupling between the Higgs field and the scalar curvature of gravity and a curvature induced contribution to the running of the constants. For the minimal set up of the standard model and a decoupled inflation sector we show how a metastable vacuum can lead to very tight bounds for the non-minimal coupling. We also discuss a novel and very much related dark matter generation mechanism.This article is part of the Theo Murphy meeting issue 'Higgs cosmology'., (© 2018 The Author(s).)
Published: 2018
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47. Inflationary potentials yielding constant scalar perturbation spectral indices

Author: Edmund J. Copeland, Edward W. Kolb, Alberto Vallinotto, Daniele A. Steer, Andrew R. Liddle, Physics Department, University of Chicago, Dipartimento di Fisica, Politecnico di Torino = Polytechnic of Turin (Polito), Department of Physics and Astronomy [Brighton] (DPA), University of Sussex, Department of Astronomy and Astrophysics, Enrico Fermi Institute, Fermilab Astrophysics Center, Fermi National Accelerator Laboratory (Fermilab), Astronomy Centre, APC - THEORIE, AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), Politecnico di Torino [Torino] (Polito), Fermi National Accelerator Laboratory, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut für theoretische Physik
Subjects: Physics, Nuclear and High Energy Physics, Spectral index, 010308 nuclear & particles physics, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], Astrophysics (astro-ph), Spectral density, Perturbation (astronomy), FOS: Physical sciences, Observable, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 16. Peace & justice, 01 natural sciences, Hamilton–Jacobi equation, Quantum electrodynamics, 0103 physical sciences, Particle-theory and field-theory models of the early Universe, 010306 general physics
Abstract: We explore the types of slow-roll inflationary potentials that result in scalar perturbations with a constant spectral index, i.e., perturbations that may be described by a single power-law spectrum over all observable scales. We devote particular attention to the type of potentials that result in the Harrison--Zel'dovich spectrum., Comment: 8 pages, 3 figures. New general derivation method, structure changed
Published: 2004

48. Fluctuating brane in a dilatonic bulk

Author: David Langlois, María Rodríguez-Martínez, Philippe Brax, Institut de Physique Théorique - UMR CNRS 3681 (IPHT), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique de Paris (IAP), and Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: High Energy Physics - Theory, Nuclear and High Energy Physics, 04.50.+h, alternative theories of gravity, FOS: Physical sciences, General Relativity and Quantum Cosmology (gr-qc), Astrophysics, General Relativity and Quantum Cosmology, High Energy Physics - Phenomenology (hep-ph), Brane cosmology, Gravity in more than four dimensions Kaluza-Klein theory unified field theories, Mathematical physics, Physics, Spacetime, 98.80.Cq, Astrophysics (astro-ph), Exponential function, High Energy Physics - Phenomenology, Classical mechanics, High Energy Physics - Theory (hep-th), [SDU]Sciences of the Universe [physics], Homogeneous, Particle-theory and field-theory models of the early Universe, Brane, Scalar field
Abstract: We consider a cosmological brane moving in a static five-dimensional bulk spacetime endowed with a scalar field whose potential is exponential. After studying various cosmological behaviours for the homogeneous background, we investigate the fluctuations of the brane that leave spacetime unaffected. A single mode embodies these fluctuations and obeys a wave equation which we study for bouncing and ever-expanding branes., Comment: 17 pages, 7 figures, revtex
Published: 2002
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49. Inflationary cosmology of the extreme cosmic string

Author: Pedro F. González-Díaz
Subjects: media_common.quotation_subject, Cosmic strings, Semiclassical physics, FOS: Physical sciences, [PACS] Extended classical solutions, Astrophysics::Cosmology and Extragalactic Astrophysics, General Relativity and Quantum Cosmology (gr-qc), Domain walls, String (physics), General Relativity and Quantum Cosmology, Theoretical physics, symbols.namesake, Minisuperspace, Texture, Planck, Eternal inflation, Mathematical Physics, media_common, Physics, Spacetime, Astronomy and Astrophysics, Quantum cosmology, Universe, Mathematical and relativistic aspects of cosmology, Cosmic string, Space and Planetary Science, symbols, Particle-theory and field-theory models of the early Universe
Abstract: Starting with a study of the cosmological solution to the Einstein equations for the internal spacetime of an extreme supermassive cosmic string kink, and by evaluating the probability measure for the formation of such a kink in semiclassical approximation using a minisuperspace with the appropriate symmetry, we have found a set of arguments in favor of the claim that the kinked extreme string can actually be regarded as an unbounded chain of pairs of Planck-sized universes. Once one such universe pairs is created along a primordial phase transition at the Planck scale, it undergoes an endless process of continuous self-regeneration driven by chaotic inflation in each of the universes forming the pair., This investigation has been supported by DGICYT under Research Project No. PB94-0107.
Published: 1998
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50. Inflationary cosmology of the extreme cosmic string

Author: González-Díaz, Pedro F. and González-Díaz, Pedro F.
Abstract: Starting with a study of the cosmological solution to the Einstein equations for the internal spacetime of an extreme supermassive cosmic string kink, and by evaluating the probability measure for the formation of such a kink in semiclassical approximation using a minisuperspace with the appropriate symmetry, we have found a set of arguments in favor of the claim that the kinked extreme string can actually be regarded as an unbounded chain of pairs of Planck-sized universes. Once one such universe pairs is created along a primordial phase transition at the Planck scale, it undergoes an endless process of continuous self-regeneration driven by chaotic inflation in each of the universes forming the pair.
Published: 1998

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