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285 results on '"A. Pourtsidou"'

251. Zipping and Unzipping in String Networks: Dynamics of Y-junctions

Author

Avgoustidis, A., Pourtsidou, A., Sakellariadou, M., Avgoustidis, A., Pourtsidou, A., and Sakellariadou, M.

Abstract

We study, within the Nambu-Goto approximation, the stability of massive string junctions under the influence of the tensions of three strings joining together in a Y-type configuration. The relative angle $\beta$ between the strings at the junction is in general time-dependent and its evolution can lead to zipping or unzipping of the three-string configuration. We find that these configurations are stable under deformations of the tension balance condition at the junction. The angle $\beta$ relaxes at its equilibrium value and the junction grows relativistically. We then discuss other potential "unzipping agents" including monopole/string forces for long strings and curvature for loops, and we investigate specific solutions exhibiting decelerated zipping and unzipping of the Y-junction. These results provide motivation for incorporating the effects of realistic string interactions in network evolution models with string junctions., Comment: 24 pages, 11 figures

Published
2014
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252. Gravitational Lensing of Cosmological 21cm Emission

Author

Pourtsidou, A., Metcalf, R. Benton, Pourtsidou, A., and Metcalf, R. Benton

Abstract

We investigate the feasibility of measuring weak gravitational lensing using 21cm intensity mapping with special emphasis on the performance of the planned Square Kilometre Array (SKA). We find that the current design for SKA-Mid should be able to measure the evolution of the lensing power spectrum at z~2-3 using this technique. This will be a probe of the expansion history of the universe and gravity at a unique range in redshift. The signal-to-noise is found to be highly dependent on evolution of the neutral hydrogen fraction in the universe with a higher HI density resulting in stronger signal. With realistic models for this, SKA Phase 1 should be capable of measuring the lensing power spectrum and its evolution. The signal-to-noise's dependence on the area and diameter of the telescope array is quantified. We further demonstrate the applications of this technique by applying it to two specific coupled dark energy models that would be difficult to observationally distinguish without information from this range of redshift. We also investigate measuring the lensing signal with 21cm emission from the Epoch of Reionization (EoR) using SKA-Low and find that it is unlikely to constrain cosmological parameters because of the small survey size, but could provide a map of the dark matter within a small region of the sky., Comment: 18 pages, 14 figures; version accepted for publication in MNRAS

Published
2014
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256. Testing gravity at large scales with HI intensity mapping.

Author

Pourtsidou, Alkistis

Subjects
ASTRONOMICAL observations, GENERAL relativity (Physics), ASTRONOMICAL models, GRAVITATIONAL lenses, COSMIC background radiation, HYDROGEN
Abstract

We investigate the possibility of testing Einstein's general theory of relativity (GR) and the standard cosmological model via the EG statistic using neutral hydrogen (H I) intensity mapping. We generalize the Fourier space estimator for EG to include HI as a biased tracer of matter and forecast statistical errors using HI clustering and lensing surveys that can be performed in the near future, in combination with ongoing and forthcoming optical galaxy and cosmic microwave background (CMB) surveys. We find that fractional errors<1 per cent in the EG measurement can be achieved in a number of cases and compare the ability of various survey combinations to differentiate between GR and specific modified gravity models. Measuring EG with intensity mapping and the Square Kilometre Array can provide exquisite tests of gravity at cosmological scales. [ABSTRACT FROM AUTHOR]

Published
2016
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261. Radio frequency interference from radio navigation satellite systems: simulations and comparison to MeerKAT single-dish data.

Author

Engelbrecht, Brandon N, Santos, Mario G, Fonseca, José, Li, Yichao, Wang, Jingying, Irfan, Melis O, Harper, Stuart E, Grainge, Keith, Bull, Philip, Carucci, Isabella P, Cunnington, Steven, Pourtsidou, Alkistis, Spinelli, Marta, and Wolz, Laura

Subjects
*RADIO interference, *ARTIFICIAL satellites in navigation, *SATELLITE radio services, *SIMULATION software, *MEERKAT
Abstract

Radio frequency interference (RFI) is emitted from various sources, terrestrial or orbital, and creates a nuisance for ground-based 21-cm experiments. In particular, single-dish observations will be highly susceptible to RFI due to their wide primary beam and sensitivity. This work aimed to simulate the contamination effects from the Radio Navigational Satellite System (RNSS) within the 1100–1350 (MHz) frequency band. The simulation can be divided into two parts: (i) satellite positioning, emission power, and the beam response on the telescope, and (ii) calibration of the satellite signals to data to improve the original model. We utilize previously observed single-dish L -band data from the Meer-Karoo Array Telescope (MeerKAT), which requires special calibration to account for regions contaminated by satellite-based RFI. We find that we can recreate the satellite contamination with high accuracy around its peak frequencies provided the satellite is not too close to the telescope's pointing direction. The simulation can predict satellite movements and signals for past and future observations, aiding in RFI avoidance and testing novel cleaning methods. The predicted signal sits below the noise in the target cosmology window in the L band (970–1015 MHz) making it difficult to confirm any out-of-band emission from satellites. However, in our simulations, this contamination still overwhelmed the 21-cm auto-power spectrum. Nevertheless, it is possible to detect the signal in cross-correlations after mild foreground cleaning. Whether such out of band contamination does exist will require further characterization of the satellite signals far away from their peak frequencies. [ABSTRACT FROM AUTHOR]

Published
2025
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262. Weak gravitational lensing with the square kilometre array

Author

Benjamin Joachimi, Ian Harrison, Michael L. Brown, P. Patel, Matt J. Jarvis, Sarah Bridle, R. B. Metcalf, Keitaro Takahashi, Joe Zuntz, D. J. Bacon, Alkistis Pourtsidou, Stefano Camera, Lance Miller, Thomas D. Kitching, F. B. Abdalla, Brown, M.L., Bacon, D.J., Camera, S., Harrison, I., Joachimi, B., Metcalf, R.B., Pourtsidou, A., Takahashi, K., Zuntz, J.A., Abdalla, F.B., Bridle, S., Jarvis, M., Kitching, T.D., Miller, L., and Patel, P.

Subjects
Physics, Multidisciplinary, Cosmology and Nongalactic Astrophysics (astro-ph.CO), 010504 meteorology & atmospheric sciences, Intensity mapping, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Redshift, Radio spectrum, Pathfinder, Square kilometre array, 0103 physical sciences, 010303 astronomy & astrophysics, Weak gravitational lensing, 0105 earth and related environmental sciences, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We investigate the capabilities of various stages of the SKA to perform world-leading weak gravitational lensing surveys. We outline a way forward to develop the tools needed for pursuing weak lensing in the radio band. We identify the key analysis challenges and the key pathfinder experiments that will allow us to address them in the run up to the SKA. We identify and summarize the unique and potentially very powerful aspects of radio weak lensing surveys, facilitated by the SKA, that can solve major challenges in the field of weak lensing. These include the use of polarization and rotational velocity information to control intrinsic alignments, and the new area of weak lensing using intensity mapping experiments. We show how the SKA lensing surveys will both complement and enhance corresponding efforts in the optical wavebands through cross-correlation techniques and by way of extending the reach of weak lensing to high redshift., Comment: 19 pages, 6 figures. Cosmology Chapter, Advancing Astrophysics with the SKA (AASKA14) Conference, Giardini Naxos (Italy), June 9th-13th 2014

263. Cosmology with a SKA HI intensity mapping survey

Author

Roy Maartens, Laura Wolz, Matt J. Jarvis, Gianni Bernardi, Mario G. Santos, David Alonso, Filipe B. Abdalla, Stefano Camera, Matteo Viel, Francisco Villaescusa-Navarro, Philip Bull, Pedro G. Ferreira, R. Benton Metcalf, Alkistis Pourtsidou, Santos, Mario G., Bull, Philip, Alonso, David, Camera, Stefano, Ferreira, Pedro G., Bernardi, Gianni, Maartens, Roy, Viel, Matteo, Villaescusa-Navarro, Francisco, Abdalla, Filipe B., Jarvis, J. Matt, Metcalf, R. Benton, Pourtsidou, A., and Wolz, Laura

Subjects
Physics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), General relativity, Intensity mapping, FOS: Physical sciences, Astronomy, General Relativity and Quantum Cosmology (gr-qc), Astrophysics::Cosmology and Extragalactic Astrophysics, Cosmology, Galaxy, General Relativity and Quantum Cosmology, cosmology, radio astronomy, Square kilometre array, Non-Gaussianity, General, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

HI intensity mapping (IM) is a novel technique capable of mapping the large-scale structure of the Universe in three dimensions and delivering exquisite constraints on cosmology, by using HI as a biased tracer of the dark matter density field. This is achieved by measuring the intensity of the redshifted 21cm line over the sky in a range of redshifts without the requirement to resolve individual galaxies. In this chapter, we investigate the potential of SKA1 to deliver HI intensity maps over a broad range of frequencies and a substantial fraction of the sky. By pinning down the baryon acoustic oscillation and redshift space distortion features in the matter power spectrum -- thus determining the expansion and growth history of the Universe -- these surveys can provide powerful tests of dark energy models and modifications to General Relativity. They can also be used to probe physics on extremely large scales, where precise measurements of spatial curvature and primordial non-Gaussianity can be used to test inflation; on small scales, by measuring the sum of neutrino masses; and at high redshifts where non-standard evolution models can be probed. We discuss the impact of foregrounds as well as various instrumental and survey design parameters on the achievable constraints. In particular we analyse the feasibility of using the SKA1 autocorrelations to probe the large-scale signal., This article is part of the 'SKA Cosmology Chapter, Advancing Astrophysics with the SKA (AASKA14), Conference, Giardini Naxos (Italy), June 9th-13th 2014'

264. H I constraints from the cross-correlation of eBOSS galaxies and Green Bank Telescope intensity maps

Author

Wolz, Laura, Pourtsidou, Alkistis, Masui, Kiyoshi W., Chang, Tzu-Ching, Bautista, Julian E., Mueller, Eva-Maria, Avila, Santiago, Bacon, David, Percival, Will J., Cunnington, Steven, Anderson, Chris, Chen, Xuelei, Kneib, Jean-Paul, Li, Yi-Chao, Liao, Yu-Wei, Pen, Ue-Li, Peterson, Jeffrey B., Rossi, Graziano, Schneider, Donald P., Yadav, Jaswant, and Zhao, Gong-Bo

Subjects
large-scale structure of universe, radio lines: galaxies, methods: statistical, 1/f noise, spectroscopic survey measurement, power spectrum, redshift 0.6, large-scale structure, mass function, cosmology: observations, cosmic neutral hydrogen, galaxies: evolution, multipole expansion, growth-rate, dark energy survey
Abstract

We present the joint analysis of Neutral Hydrogen (H I) Intensity Mapping observations with three galaxy samples: the Luminous Red Galaxy (LRG) and Emission Line Galaxy (ELG) samples from the eBOSS survey, and the WiggleZ Dark Energy Survey sample. The H I intensity maps are Green Bank Telescope observations of the redshifted 21cm emission on 100 deg(2) covering the redshift range 0.6 < z < 1.0. We process the data by separating and removing the foregrounds present in the radio frequencies with FAsTI ICA. We verify the quality of the foreground separation with mock realizations, and construct a transfer function to correct for the effects of foreground removal on the H I signal. We cross-correlate the cleaned H I data with the galaxy samples and study the overall amplitude as well as the scale dependence of the power spectrum. We also qualitatively compare our findings with the predictions by a semianalytical galaxy evolution simulation. The cross-correlations constrain the quantity Omega(H I)b(H I)r(H I,opt) at an effective scale k(eff), where Omega(H I) is the H I density fraction, b(H I )is the H I bias, and r(H I,opt) the galaxy-hydrogen correlation coefficient, which is dependent on the H I content of the optical galaxy sample. At k(eff) = 0.31 h Mpc(-1) we find Omega(H I)b(H I)r(H I,wig) = [0.58 +/- 0.09 (stat) +/- 0.05 (sys)] x 10(-3) for GBT-WiggleZ, Omega(H I)b(H I)r(H I,ELG) = [0.40 +/- 0.09 (stat) +/- 0.04 (sys)] x 10(-3) for GBT-ELG, and Omega(H I)b(H I)r(H I,LRG) = [0.35 +/- 0.08 (stat) +/- 0.03 (sys)] x 10(-3) for GBT-LRG, at z similar or equal to 0.8. We also report results at k(eff) = 0.24 and k(eff) = 0.48 h Mpc(-1). With little information on H I parameters beyond our local Universe, these are amongst the most precise constraints on neutral hydrogen density fluctuations in an underexplored redshift range.

265. Euclid preparation. XXIV. Calibration of the halo mass function in $\Lambda(\nu)$CDM cosmologies

Author

Euclid Collaboration, Castro, T., Fumagalli, A., Angulo, R. E., Bocquet, S., Borgani, S., Carbone, C., Dakin, J., Dolag, K., Giocoli, C., Monaco, P., Ragagnin, A., Saro, A., Sefusatti, E., Costanzi, M., Brun, A. M. C. Le, Corasaniti, P. -S., Amara, A., Amendola, L., Baldi, M., Bender, R., Bodendorf, C., Branchini, E., Brescia, M., Camera, S., Capobianco, V., Carretero, J., Castellano, M., Cavuoti, S., Cimatti, A., Cledassou, R., Congedo, G., Conversi, L., Copin, Y., Corcione, L., Courbin, F., Da Silva, A., Degaudenzi, H., Douspis, M., Dubath, F., Duncan, C. A. J., Dupac, X., Farrens, S., Ferriol, S., Fosalba, P., Frailis, M., Franceschi, E., Galeotta, S., Garilli, B., Gillis, B., Grazian, A., Grupp, F., Haugan, S. V. H., Hormuth, F., Hornstrup, A., Hudelot, P., Jahnke, K., Kermiche, S., Kitching, T., Kunz, M., Kurki-Suonio, H., Lilje, P. B., Lloro, I., Mansutti, O., Marggraf, O., Marulli, F., Meneghetti, M., Merlin, E., Meylan, G., Moresco, M., Moscardini, L., Munari, E., Niemi, S. M., Padilla, C., Paltani, S., Pasian, F., Pedersen, K., Pettorino, V., Pires, S., Polenta, G., Poncet, M., Popa, L., Pozzetti, L., Raison, F., Rebolo, R., Renzi, A., Rhodes, J., Riccio, G., Romelli, E., Saglia, R., Sapone, D., Sartoris, B., Schneider, P., Seidel, G., Sirri, G., Stanco, L., Crespí, P. Tallada, Taylor, A. N., Toledo-Moreo, R., Torradeflot, F., Tutusaus, I., Valentijn, E. A., Valenziano, L., Vassallo, T., Wang, Y., Weller, J., Zacchei, A., Zamorani, G., Andreon, S., Bardelli, S., Bozzo, E., Colodro-Conde, C., Di Ferdinando, D., Farina, M., Graciá-Carpio, J., Lindholm, V., Neissner, C., Scottez, V., Tenti, M., Zucca, E., Baccigalupi, C., Balaguera-Antolínez, A., Ballardini, M., Bernardeau, F., Biviano, A., Blanchard, A., Borlaff, A. S., Burigana, C., Cabanac, R., Cappi, A., Carvalho, C. S., Casas, S., Castignani, G., Cooray, A., Coupon, J., Courtois, H. M., Davini, S., De Lucia, G., Desprez, G., Dole, H., Escartin, J. A., Escoffier, S., Finelli, F., Ganga, K., Garcia-Bellido, J., George, K., Gozaliasl, G., Hildebrandt, H., Hook, I., Ilić, S., Kansal, V., Keihanen, E., Kirkpatrick, C. C., Loureiro, A., Macias-Perez, J., Magliocchetti, M., Maoli, R., Marcin, S., Martinelli, M., Martinet, N., Matthew, S., Maturi, M., Metcalf, R. B., Morgante, G., Nadathur, S., Nucita, A. A., Patrizii, L., Peel, A., Popa, V., Porciani, C., Potter, D., Pourtsidou, A., Pöntinen, M., Sánchez, A. G., Sakr, Z., Schirmer, M., Sereno, M., Mancini, A. Spurio, Teyssier, R., Valiviita, J., Veropalumbo, A., Viel, M., Centre National d'Études Spatiales [Toulouse] (CNES), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), 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), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), 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), Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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 de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (1965 - 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, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-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 des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), and Euclid

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

Euclid's photometric galaxy cluster survey has the potential to be a very competitive cosmological probe. The main cosmological probe with observations of clusters is their number count, within which the halo mass function (HMF) is a key theoretical quantity. We present a new calibration of the analytic HMF, at the level of accuracy and precision required for the uncertainty in this quantity to be subdominant with respect to other sources of uncertainty in recovering cosmological parameters from Euclid cluster counts. Our model is calibrated against a suite of N-body simulations using a Bayesian approach taking into account systematic errors arising from numerical effects in the simulation. First, we test the convergence of HMF predictions from different N-body codes, by using initial conditions generated with different orders of Lagrangian Perturbation theory, and adopting different simulation box sizes and mass resolution. Then, we quantify the effect of using different halo-finder algorithms, and how the resulting differences propagate to the cosmological constraints. In order to trace the violation of universality in the HMF, we also analyse simulations based on initial conditions characterised by scale-free power spectra with different spectral indexes, assuming both Einstein--de Sitter and standard $\Lambda$CDM expansion histories. Based on these results, we construct a fitting function for the HMF that we demonstrate to be sub-percent accurate in reproducing results from 9 different variants of the $\Lambda$CDM model including massive neutrinos cosmologies. The calibration systematic uncertainty is largely sub-dominant with respect to the expected precision of future mass-observation relations; with the only notable exception of the effect due to the halo finder, that could lead to biased cosmological inference., Comment: 25 pages, 21 figures, 5 tables, 3 appendixes; v2 matches published version

266. A large sky survey with MeerKAT

Author

Matt Hilton, Matthew Prescott, Mario G. Santos, P. Patel, Russ Taylor, Gyula I. G. Józsa, Lerothodi Leonard Leeuw, Song Chen, Philip Bull, Roy Maartens, Ian Heywood, Eliab Malefahlo, José Fonseca, I. H. Whittam, Matt J. Jarvis, Amadeus Witzemann, K. McAlpine, Alkistis Pourtsidou, Stefano Camera, Kenda Knowles, Kristine Spekkens, and Kavilan Moodley

Subjects
Computer science, Intensity mapping, Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics, Galaxy, Redshift, law.invention, Telescope, law, Dark energy, Baryon acoustic oscillations, General, Reionization, Galaxy cluster
Abstract

We discuss the ground-breaking science that will be possible with a wide area survey, using the MeerKAT telescope, known as MeerKLASS (MeerKAT Large Area Synoptic Survey). The current specifications of MeerKAT make it a great fit for cosmological applications, which require large volumes. In particular, a large survey over $\sim 4,000 \, {\rm deg}^2$ for $\sim 4,000$ hours will potentially provide the first ever measurements of the baryon acoustic oscillations using the 21cm intensity mapping technique, with enough accuracy to impose constraints on the nature of dark energy. The combination with multi-wavelength data will give unique additional information, such as the first constraints on primordial non-Gaussianity using the multi-tracer technique, as well as a better handle on foregrounds and systematics. The survey will also produce a large continuum galaxy sample down to a depth of 5\,$\mu$Jy in L-band, unmatched by any other concurrent telescope, which will allow to study the large-scale structure of the Universe out to high redshifts. Finally, the same survey will supply unique information for a range of other science applications, including a large statistical investigation of galaxy clusters, and the discovery of rare high-redshift AGN that can be used to probe the epoch of reionization as well as produce a rotation measure map across a huge swathe of the sky. The MeerKLASS survey will be a crucial step on the road to using SKA1-MID for cosmological applications, as described in the top priority SKA key science projects.

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267. MeerKLASS: MeerKAT large area synoptic survey

Author

Santos, MG, Cluver, M, Hilton, M, Jarvis, M, Jozsa, GIG, Leeuw, L, Smirnov, O, Taylor, R, Abdalla, F, Afonso, J, Alonso, D, Bacon, D, Bassett, BA, Bernardi, G, Bull, P, Camera, S, Chiang, HC, Colafrancesco, S, Ferreira, PG, Fonseca, J, Heyden, KVD, Heywood, I, Knowles, K, Lochner, M, Ma, Y-Z, Maartens, R, Makhathini, S, Moodley, K, Pourtsidou, A, Prescott, M, Sievers, J, Spekkens, K, Vaccari, M, Weltman, A, Whittam, I, Witzemann, A, Wolz, L, and Zwart, JTL

Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We discuss the ground-breaking science that will be possible with a wide area survey, using the MeerKAT telescope, known as MeerKLASS (MeerKAT Large Area Synoptic Survey). The current specifications of MeerKAT make it a great fit for science applications that require large survey speeds but not necessarily high angular resolutions. In particular, for cosmology, a large survey over $\sim 4,000 \, {\rm deg}^2$ for $\sim 4,000$ hours will potentially provide the first ever measurements of the baryon acoustic oscillations using the 21cm intensity mapping technique, with enough accuracy to impose constraints on the nature of dark energy. The combination with multi-wavelength data will give unique additional information, such as exquisite constraints on primordial non-Gaussianity using the multi-tracer technique, as well as a better handle on foregrounds and systematics. Such a wide survey with MeerKAT is also a great match for HI galaxy studies, providing unrivalled statistics in the pre-SKA era for galaxies resolved in the HI emission line beyond local structures at z > 0.01. It will also produce a large continuum galaxy sample down to a depth of about 5\,$��$Jy in L-band, which is quite unique over such large areas and will allow studies of the large-scale structure of the Universe out to high redshifts, complementing the galaxy HI survey to form a transformational multi-wavelength approach to study galaxy dynamics and evolution. Finally, the same survey will supply unique information for a range of other science applications, including a large statistical investigation of galaxy clusters as well as produce a rotation measure map across a huge swathe of the sky. The MeerKLASS survey will be a crucial step on the road to using SKA1-MID for cosmological applications and other commensal surveys, as described in the top priority SKA key science projects (abridged)., Larger version of the paper submitted to the Proceedings of Science, "MeerKAT Science: On the Pathway to the SKA", Stellenbosch, 25-27 May 2016

268. Euclid preparation: XXVIII. Modelling of the weak lensing angular power spectrum

Author

Euclid Collaboration, Deshpande, A. C., Kitching, T., Hall, A., Brown, M. L., Aghanim, N., Amendola, L., Auricchio, N., Baldi, M., Bender, R., Bonino, D., Branchini, E., Brescia, M., Brinchmann, J., Camera, S., Candini, G. P., Capobianco, V., Carbone, C., Cardone, V. F., Carretero, J., Castander, F. J., Castellano, M., Cavuoti, S., Cimatti, A., Cledassou, R., Congedo, G., Conselice, C. J., Conversi, L., Corcione, L., Courbin, F., Cropper, M., Da Silva, A., Degaudenzi, H., Douspis, M., Dubath, F., Duncan, C. A. J., Dupac, X., Farrens, S., Ferriol, S., Fosalba, P., Frailis, M., Franceschi, E., Fumana, M., Galeotta, S., Garilli, B., Gillis, B., Giocoli, C., Grazian, A., Grupp, F., Haugan, S. V. H., Hoekstra, H., Holmes, W., Hornstrup, A., Hudelot, P., Jahnke, K., Kermiche, S., Kilbinger, M., Kunz, M., Kurki-Suonio, H., Ligori, S., Lilje, P. B., Lloro, I., Maiorano, E., Mansutti, O., Marggraf, O., Markovic, K., Marulli, F., Massey, R., Mei, S., Mellier, Y., Meneghetti, M., Meylan, G., Moscardini, L., Niemi, S. -M., Nightingale, J. W., Nutma, T., Padilla, C., Paltani, S., Pasian, F., Pedersen, K., Pettorino, V., Pires, S., Polenta, G., Poncet, M., Popa, L. A., Raison, F., Renzi, A., Rhodes, J., Riccio, G., Romelli, E., Roncarelli, M., Rossetti, E., Saglia, R., Sapone, D., Sartoris, B., Schneider, P., Schrabback, T., Secroun, A., Seidel, G., Serrano, S., Sirignano, C., Sirri, G., Stanco, L., Tallada-Crespi, P., Tereno, I., Toledo-Moreo, R., Torradeflot, F., Tutusaus, I., Valentijn, E. A., Valenziano, L., Vassallo, T., Wang, Y., Weller, J., Zacchei, A., Zamorani, G., Zoubian, J., Andreon, S., Bardelli, S., Boucaud, A., Bozzo, E., Colodro-Conde, C., Di Ferdinando, D., Fabbian, G., Farina, M., Gracia-Carpio, J., Keihanen, E., Lindholm, V., Mauri, N., Scottez, V., Tenti, M., Zucca, E., Akrami, Y., Baccigalupi, C., Balaguera-Antolinez, A., Ballardini, M., Bernardeau, F., Biviano, A., Blanchard, A., Borlaff, A. S., Burigana, C., Cabanac, R., Cappi, A., Carvalho, C. S., Casas, S., Castignani, G., Castro, T., Chambers, K. C., Cooray, A. R., Coupon, J., Courtois, H. M., Davini, S., de la Torre, S., De Lucia, G., Desprez, G., Dole, H., Escartin, J. A., Escoffier, S., Ferrero, I., Finelli, F., Garcia-Bellido, J., George, K., Giacomini, F., Gozaliasl, G., Hildebrandt, H., Kajava, J. J. E., Kansal, V., Kirkpatrick, C. C., Legrand, L., Loureiro, A., Macias-Perez, J., Magliocchetti, M., Mainetti, G., Maoli, R., Martinelli, M., Martinet, N., Martins, C. J. A. P., Matthew, S., Maurin, L., Metcalf, R. B., Monaco, P., Morgante, G., Nadathur, S., Nucita, A. A., Patrizii, L., Peel, A., Pollack, J., Popa, V., Porciani, C., Potter, D., Pourtsidou, A., Pontinen, M., Reimberg, P., Sanchez, A. G., Sakr, Z., Schneider, A., Sefusatti, E., Sereno, M., Shulevski, A., Mancini, A. Spurio, Steinwagner, J., Teyssier, R., Viel, M., Zinchenko, I. A., Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Centre National d'Études Spatiales [Toulouse] (CNES), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), 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), 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), Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-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)), 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), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique de l'ENS - ENS Paris (LPENS), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Département de Physique de l'ENS-PSL, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), 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), Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (1965 - 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, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Centre de Calcul de l'IN2P3 (CC-IN2P3), 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), Euclid, and HEP, INSPIRE

Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO), Gravitational lensing: weak, Cosmology: observations, FOS: Physical sciences, Methods: analytical, [PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

This work considers which higher-order effects in modelling the cosmic shear angular power spectra must be taken into account for Euclid. We identify which terms are of concern, and quantify their individual and cumulative impact on cosmological parameter inference from Euclid. We compute the values of these higher-order effects using analytic expressions, and calculate the impact on cosmological parameter estimation using the Fisher matrix formalism. We review 24 effects and find the following potentially need to be accounted for: the reduced shear approximation, magnification bias, source-lens clustering, source obscuration, local Universe effects, and the flat Universe assumption. Upon computing these explicitly, and calculating their cosmological parameter biases, using a maximum multipole of $\ell=5000$, we find that the magnification bias, source-lens clustering, source obscuration, and local Universe terms individually produce significant ($\,>0.25\sigma$) cosmological biases in one or more parameters, and accordingly must be accounted for. In total, over all effects, we find biases in $\Omega_{\rm m}$, $\Omega_{\rm b}$, $h$, and $\sigma_{8}$ of $0.73\sigma$, $0.28\sigma$, $0.25\sigma$, and $-0.79\sigma$, respectively, for flat $\Lambda$CDM. For the $w_0w_a$CDM case, we find biases in $\Omega_{\rm m}$, $\Omega_{\rm b}$, $h$, $n_{\rm s}$, $\sigma_{8}$, and $w_a$ of $1.49\sigma$, $0.35\sigma$, $-1.36\sigma$, $1.31\sigma$, $-0.84\sigma$, and $-0.35\sigma$, respectively; which are increased relative to the $\Lambda$CDM due to additional degeneracies as a function of redshift and scale., Comment: 20 pages, submitted to A&A

269. Euclid preparation: XXXI. The effect of the variations in photometric passbands on photometric-redshift accuracy

Author

Paltani, S., Coupon, J., Hartley, W. G., Alvarez-Ayllon, A., Dubath, F., Mohr, J. J., Schirmer, M., Cuillandre, J.-C., Desprez, G., Ilbert, O., Kuijken, K., Aghanim, N., Altieri, B., Amara, A., Auricchio, N., Baldi, M., Bender, R., Bodendorf, C., Bonino, D., Branchini, E., Brescia, M., Brinchmann, J., Camera, S., Capobianco, V., Carbone, C., Cardone, V. F., Carretero, J., Castander, F. J., Castellano, M., Cavuoti, S., Cledassou, R., Congedo, G., Conselice, C. J., Conversi, L., Copin, Y., Corcione, L., Courbin, F., Cropper, M., Da Silva, A., Degaudenzi, H., Dinis, J., Douspis, M., Dupac, X., Dusini, S., Farrens, S., Ferriol, S., Fosalba, P., Frailis, M., Franceschi, E., Franzetti, P., Galeotta, S., Garilli, B., Gillard, W., Gillis, B., Giocoli, C., Grazian, A., Haugan, S. V., Hoekstra, H., Hornstrup, A., Hudelot, P., Jahnke, K., Kümmel, M., Kermiche, S., Kiessling, A., Kilbinger, M., Kitching, T., Kohley, R., Kubik, B., Kunz, M., Kurki-Suonio, H., Ligori, S., Lilje, P. B., Lloro, I., Maiorano, E., Mansutti, O., Marggraf, O., Markovic, K., Marulli, F., Massey, R., Masters, D. C., Maurogordato, S., McCracken, H. J., Medinaceli, E., Mei, S., Melchior, M., Meneghetti, M., Merlin, E., Meylan, G., Moresco, M., Moscardini, L., Munari, E., Niemi, S.-M., Nightingale, J., Padilla, C., Pasian, F., Pedersen, K., Percival, W. J., Pettorino, V., Polenta, G., Poncet, M., Popa, L. A., Raison, F., Rebolo, R., Renzi, A., Rhodes, J., Riccio, G., Romelli, E., Roncarelli, M., Rossetti, E., Saglia, R., Sapone, D., Sartoris, B., Schneider, P., Secroun, A., Sirignano, C., Sirri, G., Skottfelt, J., Stanco, L., Starck, J.-L., Surace, C., Tallada-Crespí, P., Tereno, I., Toledo-Moreo, R., Torradeflot, F., Tutusaus, I., Valentijn, E. A., Valenziano, L., Vassallo, T., Wang, Y., Zamorani, G., Zoubian, J., Andreon, S., Aussel, H., Bardelli, S., Bolzonella, M., Boucaud, A., Di Ferdinando, D., Farina, M., Graciá-Carpio, J., Lindholm, V., Maino, D., Mauri, N., Neissner, C., Scottez, V., Zucca, E., Baccigalupi, C., Ballardini, M., Biviano, A., Blanchard, A., Borgani, S., Borlaff, A. S., Burigana, C., Cabanac, R., Cappi, A., Carvalho, C. S., Casas, S., Castignani, G., Chambers, K., Cooray, A. R., Courtois, H. M., Cucciati, O., Davini, S., De Lucia, G., Dole, H., Escartin, J. A., Escoffier, S., Finelli, F., Fotopoulou, S., Ganga, K., George, K., Gozaliasl, G., Hildebrandt, H., Hook, I., Jimenez Muñoz, A., Joachimi, B., Kansal, V., Keihanen, E., Kirkpatrick, C. C., Loureiro, A., Macias-Perez, J., Maggio, G., Magliocchetti, M., Maoli, R., Marcin, S., Martinelli, M., Martinet, N., Matthew, S., Maurin, L., Metcalf, R. B., Monaco, P., Morgante, G., Nadathur, S., Nucita, A. A., Patrizii, L., Pollack, J. E., Popa, V., Porciani, C., Potter, D., Pourtsidou, A., Pozzetti, L., Pöntinen, M., Reimberg, P., Sánchez, A. G., Sakr, Z., Sefusatti, E., Sereno, M., Spurio Mancini, A., Stadel, J., Steinwagner, J., Teyssier, R., Valieri, C., Valiviita, J., van Mierlo, S. E., Veropalumbo, A., Viel, M., Weaver, J. R., Paltani, S., Coupon, J., Hartley, W. G., Alvarez-Ayllon, A., Dubath, F., Mohr, J. J., Schirmer, M., Cuillandre, J.-C., Desprez, G., Ilbert, O., Kuijken, K., Aghanim, N., Altieri, B., Amara, A., Auricchio, N., Baldi, M., Bender, R., Bodendorf, C., Bonino, D., Branchini, E., Brescia, M., Brinchmann, J., Camera, S., Capobianco, V., Carbone, C., Cardone, V. F., Carretero, J., Castander, F. J., Castellano, M., Cavuoti, S., Cledassou, R., Congedo, G., Conselice, C. J., Conversi, L., Copin, Y., Corcione, L., Courbin, F., Cropper, M., Da Silva, A., Degaudenzi, H., Dinis, J., Douspis, M., Dupac, X., Dusini, S., Farrens, S., Ferriol, S., Fosalba, P., Frailis, M., Franceschi, E., Franzetti, P., Galeotta, S., Garilli, B., Gillard, W., Gillis, B., Giocoli, C., Grazian, A., Haugan, S. V., Hoekstra, H., Hornstrup, A., Hudelot, P., Jahnke, K., Kümmel, M., Kermiche, S., Kiessling, A., Kilbinger, M., Kitching, T., Kohley, R., Kubik, B., Kunz, M., Kurki-Suonio, H., Ligori, S., Lilje, P. B., Lloro, I., Maiorano, E., Mansutti, O., Marggraf, O., Markovic, K., Marulli, F., Massey, R., Masters, D. C., Maurogordato, S., McCracken, H. J., Medinaceli, E., Mei, S., Melchior, M., Meneghetti, M., Merlin, E., Meylan, G., Moresco, M., Moscardini, L., Munari, E., Niemi, S.-M., Nightingale, J., Padilla, C., Pasian, F., Pedersen, K., Percival, W. J., Pettorino, V., Polenta, G., Poncet, M., Popa, L. A., Raison, F., Rebolo, R., Renzi, A., Rhodes, J., Riccio, G., Romelli, E., Roncarelli, M., Rossetti, E., Saglia, R., Sapone, D., Sartoris, B., Schneider, P., Secroun, A., Sirignano, C., Sirri, G., Skottfelt, J., Stanco, L., Starck, J.-L., Surace, C., Tallada-Crespí, P., Tereno, I., Toledo-Moreo, R., Torradeflot, F., Tutusaus, I., Valentijn, E. A., Valenziano, L., Vassallo, T., Wang, Y., Zamorani, G., Zoubian, J., Andreon, S., Aussel, H., Bardelli, S., Bolzonella, M., Boucaud, A., Di Ferdinando, D., Farina, M., Graciá-Carpio, J., Lindholm, V., Maino, D., Mauri, N., Neissner, C., Scottez, V., Zucca, E., Baccigalupi, C., Ballardini, M., Biviano, A., Blanchard, A., Borgani, S., Borlaff, A. S., Burigana, C., Cabanac, R., Cappi, A., Carvalho, C. S., Casas, S., Castignani, G., Chambers, K., Cooray, A. R., Courtois, H. M., Cucciati, O., Davini, S., De Lucia, G., Dole, H., Escartin, J. A., Escoffier, S., Finelli, F., Fotopoulou, S., Ganga, K., George, K., Gozaliasl, G., Hildebrandt, H., Hook, I., Jimenez Muñoz, A., Joachimi, B., Kansal, V., Keihanen, E., Kirkpatrick, C. C., Loureiro, A., Macias-Perez, J., Maggio, G., Magliocchetti, M., Maoli, R., Marcin, S., Martinelli, M., Martinet, N., Matthew, S., Maurin, L., Metcalf, R. B., Monaco, P., Morgante, G., Nadathur, S., Nucita, A. A., Patrizii, L., Pollack, J. E., Popa, V., Porciani, C., Potter, D., Pourtsidou, A., Pozzetti, L., Pöntinen, M., Reimberg, P., Sánchez, A. G., Sakr, Z., Sefusatti, E., Sereno, M., Spurio Mancini, A., Stadel, J., Steinwagner, J., Teyssier, R., Valieri, C., Valiviita, J., van Mierlo, S. E., Veropalumbo, A., Viel, M., and Weaver, J. R.

270. Euclid preparation. XXVI. The Euclid Morphology Challenge: Towards structural parameters for billions of galaxies

Author

Bretonnière, H., Kuchner, U., Huertas-Company, M., Merlin, E., Castellano, M., Tuccillo, D., Buitrago, F., Conselice, C. J., Boucaud, A., Häußler, B., Kümmel, M., Hartley, W. G., Alvarez Ayllon, A., Bertin, E., Ferrari, F., Ferreira, L., Gavazzi, R., Hernández-Lang, D., Lucatelli, G., Robotham, A. S. G., Schefer, M., Wang, L., Cabanac, R., Domínguez Sánchez, H., Duc, P.-A., Fotopoulou, S., Kruk, S., La Marca, A., Margalef-Bentabol, B., Marleau, F. R., Tortora, C., Aghanim, N., Amara, A., Auricchio, N., Azzollini, R., Baldi, M., Bender, R., Bodendorf, C., Branchini, E., Brescia, M., Brinchmann, J., Camera, S., Capobianco, V., Carbone, C., Carretero, J., Castander, F. J., Cavuoti, S., Cimatti, A., Cledassou, R., Congedo, G., Conversi, L., Copin, Y., Corcione, L., Courbin, F., Cropper, M., Da Silva, A., Degaudenzi, H., Dinis, J., Dubath, F., Duncan, C. A. J., Dupac, X., Dusini, S., Farrens, S., Ferriol, S., Frailis, M., Franceschi, E., Fumana, M., Galeotta, S., Garilli, B., Gillis, B., Giocoli, C., Grazian, A., Grupp, F., Haugan, S. V. H., Hoekstra, H., Holmes, W., Hormuth, F., Hornstrup, A., Hudelot, P., Jahnke, K., Kermiche, S., Kiessling, A., Kohley, R., Kunz, M., Kurki-Suonio, H., Ligori, S., Lilje, P. B., Lloro, I., Mansutti, O., Marggraf, O., Markovic, K., Marulli, F., Massey, R., McCracken, H. J., Medinaceli, E., Melchior, M., Meneghetti, M., Meylan, G., Moresco, M., Moscardini, L., Munari, E., Niemi, S. M., Padilla, C., Paltani, S., Pasian, F., Pedersen, K., Percival, W., Pettorino, V., Polenta, G., Poncet, M., Pozzetti, L., Raison, F., Rebolo, R., Renzi, A., Rhodes, J., Riccio, G., Romelli, E., Rosset, C., Rossetti, E., Saglia, R., Sapone, D., Sartoris, B., Schneider, P., Secroun, A., Seidel, G., Sirignano, C., Sirri, G., Skottfelt, J., Starck, J.-L., Tallada-Crespí, P., Taylor, A. N., Tereno, I., Toledo-Moreo, R., Tutusaus, I., Valentijn, E. A., Valenziano, L., Vassallo, T., Wang, Y., Weller, J., Zamorani, G., Zoubian, J., Andreon, S., Bardelli, S., Colodro-Conde, C., Di Ferdinando, D., Graciá-Carpio, J., Lindholm, V., Mauri, N., Mei, S., Scottez, V., Zucca, E., Baccigalupi, C., Ballardini, M., Bernardeau, F., Biviano, A., Borgani, S., Borlaff, A. S., Burigana, C., Cappi, A., Carvalho, C. S., Casas, S., Castignani, G., Cooray, A. R., Coupon, J., Courtois, H. M., Davini, S., De Lucia, G., Desprez, G., Escartin, J. A., Escoffier, S., Fabricius, M., Farina, M., Fontana, A., Ganga, K., Garcia-Bellido, J., George, K., Gozaliasl, G., Hildebrandt, H., Hook, I., Ilbert, O., Ilić, S., Joachimi, B., Kansal, V., Keihanen, E., Kirkpatrick, C. C., Loureiro, A., Macias-Perez, J., Magliocchetti, M., Maoli, R., Marcin, S., Martinelli, M., Martinet, N., Maturi, M., Monaco, P., Morgante, G., Nadathur, S., Nucita, A. A., Patrizii, L., Popa, V., Porciani, C., Potter, D., Pourtsidou, A., Pöntinen, M., Reimberg, P., Sánchez, A. G., Sakr, Z., Schirmer, M., Sefusatti, E., Sereno, M., Stadel, J., Teyssier, R., Valiviita, J., van Mierlo, S. E., Veropalumbo, A., Viel, M., Weaver, J. R., Scott, D., Bretonnière, H., Kuchner, U., Huertas-Company, M., Merlin, E., Castellano, M., Tuccillo, D., Buitrago, F., Conselice, C. J., Boucaud, A., Häußler, B., Kümmel, M., Hartley, W. G., Alvarez Ayllon, A., Bertin, E., Ferrari, F., Ferreira, L., Gavazzi, R., Hernández-Lang, D., Lucatelli, G., Robotham, A. S. G., Schefer, M., Wang, L., Cabanac, R., Domínguez Sánchez, H., Duc, P.-A., Fotopoulou, S., Kruk, S., La Marca, A., Margalef-Bentabol, B., Marleau, F. R., Tortora, C., Aghanim, N., Amara, A., Auricchio, N., Azzollini, R., Baldi, M., Bender, R., Bodendorf, C., Branchini, E., Brescia, M., Brinchmann, J., Camera, S., Capobianco, V., Carbone, C., Carretero, J., Castander, F. J., Cavuoti, S., Cimatti, A., Cledassou, R., Congedo, G., Conversi, L., Copin, Y., Corcione, L., Courbin, F., Cropper, M., Da Silva, A., Degaudenzi, H., Dinis, J., Dubath, F., Duncan, C. A. J., Dupac, X., Dusini, S., Farrens, S., Ferriol, S., Frailis, M., Franceschi, E., Fumana, M., Galeotta, S., Garilli, B., Gillis, B., Giocoli, C., Grazian, A., Grupp, F., Haugan, S. V. H., Hoekstra, H., Holmes, W., Hormuth, F., Hornstrup, A., Hudelot, P., Jahnke, K., Kermiche, S., Kiessling, A., Kohley, R., Kunz, M., Kurki-Suonio, H., Ligori, S., Lilje, P. B., Lloro, I., Mansutti, O., Marggraf, O., Markovic, K., Marulli, F., Massey, R., McCracken, H. J., Medinaceli, E., Melchior, M., Meneghetti, M., Meylan, G., Moresco, M., Moscardini, L., Munari, E., Niemi, S. M., Padilla, C., Paltani, S., Pasian, F., Pedersen, K., Percival, W., Pettorino, V., Polenta, G., Poncet, M., Pozzetti, L., Raison, F., Rebolo, R., Renzi, A., Rhodes, J., Riccio, G., Romelli, E., Rosset, C., Rossetti, E., Saglia, R., Sapone, D., Sartoris, B., Schneider, P., Secroun, A., Seidel, G., Sirignano, C., Sirri, G., Skottfelt, J., Starck, J.-L., Tallada-Crespí, P., Taylor, A. N., Tereno, I., Toledo-Moreo, R., Tutusaus, I., Valentijn, E. A., Valenziano, L., Vassallo, T., Wang, Y., Weller, J., Zamorani, G., Zoubian, J., Andreon, S., Bardelli, S., Colodro-Conde, C., Di Ferdinando, D., Graciá-Carpio, J., Lindholm, V., Mauri, N., Mei, S., Scottez, V., Zucca, E., Baccigalupi, C., Ballardini, M., Bernardeau, F., Biviano, A., Borgani, S., Borlaff, A. S., Burigana, C., Cappi, A., Carvalho, C. S., Casas, S., Castignani, G., Cooray, A. R., Coupon, J., Courtois, H. M., Davini, S., De Lucia, G., Desprez, G., Escartin, J. A., Escoffier, S., Fabricius, M., Farina, M., Fontana, A., Ganga, K., Garcia-Bellido, J., George, K., Gozaliasl, G., Hildebrandt, H., Hook, I., Ilbert, O., Ilić, S., Joachimi, B., Kansal, V., Keihanen, E., Kirkpatrick, C. C., Loureiro, A., Macias-Perez, J., Magliocchetti, M., Maoli, R., Marcin, S., Martinelli, M., Martinet, N., Maturi, M., Monaco, P., Morgante, G., Nadathur, S., Nucita, A. A., Patrizii, L., Popa, V., Porciani, C., Potter, D., Pourtsidou, A., Pöntinen, M., Reimberg, P., Sánchez, A. G., Sakr, Z., Schirmer, M., Sefusatti, E., Sereno, M., Stadel, J., Teyssier, R., Valiviita, J., van Mierlo, S. E., Veropalumbo, A., Viel, M., Weaver, J. R., and Scott, D.

271. Cosmic strings with junctions : dynamics and cosmological implications

Author

Pourtsidou, Alkistis and Pourtsidou, Alkistis

Abstract

Cosmic strings are linear concentrations of energy that may have been formed after cosmological phase transitions in the early universe. Cosmic superstrings are analogous objects arising in string theory, and in particular in models of brane inflation. The latter possess two particular features, which differentiate them from the ordinary cosmic strings: a reduced intercommuting probability, and the ability to form junctions. This thesis is concerned with the dynamics and cosmological implications of cosmic strings and superstrings with junctions. In Chapter1, we give a brief introduction to the standard Big Bang model and t he inflationary paradigm. W e also discuss cosmic string formation after the spontaneous breaking of an Abelian U (I) gauge symmetry in the early Universe. In Chapter 2, we present an overview of cosmic string dynamics using the Nambu-Goto method. We discuss the properties of individual cosmic string segments and loops, as well as network evolution in an expanding Universe. We also introduce cosmic superstrings, and review the Nambu-Goto approach to study the evolution of junctions and the kinematic constraints that govern their formation. We conclude with the study of junctions in an expanding spacetime and present an exact solution for a closed loop of three strings and two junctions in a de Sitter Universe. In Chapter3, we compare the two different approaches developed to study the dynamics of strings with junctions. We first extensively study the dynamics and stability of a cosmic string loop with junctions using the modified Nambu-Goto approach. Comparing our results with a field theory model that permits junctions we find very good agreement. The Nambu-Goto method is once again confirmed to be a good approximation for studying cosmic string configurations. In Chapter4, we review the observational signatures of cosmic strings. More specifically, we concentrate on their gravitational effects, discussing results and constraints from lensing, g

272. Cosmic strings with junctions : dynamics and cosmological implications

Author

Pourtsidou, Alkistis and Pourtsidou, Alkistis

Abstract

Cosmic strings are linear concentrations of energy that may have been formed after cosmological phase transitions in the early universe. Cosmic superstrings are analogous objects arising in string theory, and in particular in models of brane inflation. The latter possess two particular features, which differentiate them from the ordinary cosmic strings: a reduced intercommuting probability, and the ability to form junctions. This thesis is concerned with the dynamics and cosmological implications of cosmic strings and superstrings with junctions. In Chapter1, we give a brief introduction to the standard Big Bang model and t he inflationary paradigm. W e also discuss cosmic string formation after the spontaneous breaking of an Abelian U (I) gauge symmetry in the early Universe. In Chapter 2, we present an overview of cosmic string dynamics using the Nambu-Goto method. We discuss the properties of individual cosmic string segments and loops, as well as network evolution in an expanding Universe. We also introduce cosmic superstrings, and review the Nambu-Goto approach to study the evolution of junctions and the kinematic constraints that govern their formation. We conclude with the study of junctions in an expanding spacetime and present an exact solution for a closed loop of three strings and two junctions in a de Sitter Universe. In Chapter3, we compare the two different approaches developed to study the dynamics of strings with junctions. We first extensively study the dynamics and stability of a cosmic string loop with junctions using the modified Nambu-Goto approach. Comparing our results with a field theory model that permits junctions we find very good agreement. The Nambu-Goto method is once again confirmed to be a good approximation for studying cosmic string configurations. In Chapter4, we review the observational signatures of cosmic strings. More specifically, we concentrate on their gravitational effects, discussing results and constraints from lensing, g

273. Cosmic strings with junctions : dynamics and cosmological implications

Author

Pourtsidou, Alkistis and Pourtsidou, Alkistis

Abstract

Cosmic strings are linear concentrations of energy that may have been formed after cosmological phase transitions in the early universe. Cosmic superstrings are analogous objects arising in string theory, and in particular in models of brane inflation. The latter possess two particular features, which differentiate them from the ordinary cosmic strings: a reduced intercommuting probability, and the ability to form junctions. This thesis is concerned with the dynamics and cosmological implications of cosmic strings and superstrings with junctions. In Chapter1, we give a brief introduction to the standard Big Bang model and t he inflationary paradigm. W e also discuss cosmic string formation after the spontaneous breaking of an Abelian U (I) gauge symmetry in the early Universe. In Chapter 2, we present an overview of cosmic string dynamics using the Nambu-Goto method. We discuss the properties of individual cosmic string segments and loops, as well as network evolution in an expanding Universe. We also introduce cosmic superstrings, and review the Nambu-Goto approach to study the evolution of junctions and the kinematic constraints that govern their formation. We conclude with the study of junctions in an expanding spacetime and present an exact solution for a closed loop of three strings and two junctions in a de Sitter Universe. In Chapter3, we compare the two different approaches developed to study the dynamics of strings with junctions. We first extensively study the dynamics and stability of a cosmic string loop with junctions using the modified Nambu-Goto approach. Comparing our results with a field theory model that permits junctions we find very good agreement. The Nambu-Goto method is once again confirmed to be a good approximation for studying cosmic string configurations. In Chapter4, we review the observational signatures of cosmic strings. More specifically, we concentrate on their gravitational effects, discussing results and constraints from lensing, g

274. Euclid preparation. XXV. The Euclid Morphology Challenge: Towards model-fitting photometry for billions of galaxies

Author

Merlin, E., Castellano, M., Bretonnière, H., Huertas-Company, M., Kuchner, U., Tuccillo, D., Buitrago, F., Peterson, J. R., Conselice, C. J., Caro, F., Dimauro, P., Nemani, L., Fontana, A., Kümmel, M., Häußler, B., Hartley, W. G., Alvarez Ayllon, A., Bertin, E., Dubath, P., Ferrari, F., Ferreira, L., Gavazzi, R., Hernández-Lang, D., Lucatelli, G., Robotham, A. S. G., Schefer, M., Tortora, C., Aghanim, N., Amara, A., Amendola, L., Auricchio, N., Baldi, M., Bender, R., Bodendorf, C., Branchini, E., Brescia, M., Camera, S., Capobianco, V., Carbone, C., Carretero, J., Castander, F. J., Cavuoti, S., Cimatti, A., Cledassou, R., Congedo, G., Conversi, L., Copin, Y., Corcione, L., Courbin, F., Cropper, M., Da Silva, A., Degaudenzi, H., Dinis, J., Douspis, M., Dubath, F., Duncan, C. A. J., Dupac, X., Dusini, S., Farrens, S., Ferriol, S., Frailis, M., Franceschi, E., Franzetti, P., Galeotta, S., Garilli, B., Gillis, B., Giocoli, C., Grazian, A., Grupp, F., Haugan, S. V. H., Hoekstra, H., Holmes, W., Hormuth, F., Hornstrup, A., Hudelot, P., Jahnke, K., Kermiche, S., Kiessling, A., Kitching, T., Kohley, R., Kunz, M., Kurki-Suonio, H., Ligori, S., Lilje, P. B., Lloro, I., Mansutti, O., Marggraf, O., Markovic, K., Marulli, F., Massey, R., McCracken, H. J., Medinaceli, E., Melchior, M., Meneghetti, M., Meylan, G., Moresco, M., Moscardini, L., Munari, E., Niemi, S. M., Padilla, C., Paltani, S., Pasian, F., Pedersen, K., Percival, W. J., Polenta, G., Poncet, M., Popa, L., Pozzetti, L., Raison, F., Rebolo, R., Renzi, A., Rhodes, J., Riccio, G., Romelli, E., Rossetti, E., Saglia, R., Sapone, D., Sartoris, B., Schneider, P., Secroun, A., Seidel, G., Sirignano, C., Sirri, G., Skottfelt, J., Starck, J.-L., Tallada-Crespí, P., Taylor, A. N., Tereno, I., Toledo-Moreo, R., Tutusaus, I., Valenziano, L., Vassallo, T., Wang, Y., Weller, J., Zacchei, A., Zamorani, G., Zoubian, J., Andreon, S., Bardelli, S., Boucaud, A., Colodro-Conde, C., Di Ferdinando, D., Graciá-Carpio, J., Lindholm, V., Mauri, N., Mei, S., Neissner, C., Scottez, V., Tramacere, A., Zucca, E., Baccigalupi, C., Balaguera-Antolínez, A., Ballardini, M., Bernardeau, F., Biviano, A., Borgani, S., Borlaff, A. S., Burigana, C., Cabanac, R., Cappi, A., Carvalho, C. S., Casas, S., Castignani, G., Cooray, A. R., Coupon, J., Courtois, H. M., Cucciati, O., Davini, S., De Lucia, G., Desprez, G., Escartin, J. A., Escoffier, S., Farina, M., Ganga, K., Garcia-Bellido, J., George, K., Gozaliasl, G., Hildebrandt, H., Hook, I., Ilbert, O., Ilić, S., Joachimi, B., Kansal, V., Keihanen, E., Kirkpatrick, C. C., Loureiro, A., Macias-Perez, J., Magliocchetti, M., Mainetti, G., Maoli, R., Marcin, S., Martinelli, M., Martinet, N., Matthew, S., Maturi, M., Metcalf, R. B., Monaco, P., Morgante, G., Nadathur, S., Nucita, A. A., Patrizii, L., Popa, V., Porciani, C., Potter, D., Pourtsidou, A., Pöntinen, M., Reimberg, P., Sánchez, A. G., Sakr, Z., Schirmer, M., Sereno, M., Stadel, J., Teyssier, R., Valieri, C., Valiviita, J., van Mierlo, S. E., Veropalumbo, A., Viel, M., Weaver, J. R., Scott, D., Merlin, E., Castellano, M., Bretonnière, H., Huertas-Company, M., Kuchner, U., Tuccillo, D., Buitrago, F., Peterson, J. R., Conselice, C. J., Caro, F., Dimauro, P., Nemani, L., Fontana, A., Kümmel, M., Häußler, B., Hartley, W. G., Alvarez Ayllon, A., Bertin, E., Dubath, P., Ferrari, F., Ferreira, L., Gavazzi, R., Hernández-Lang, D., Lucatelli, G., Robotham, A. S. G., Schefer, M., Tortora, C., Aghanim, N., Amara, A., Amendola, L., Auricchio, N., Baldi, M., Bender, R., Bodendorf, C., Branchini, E., Brescia, M., Camera, S., Capobianco, V., Carbone, C., Carretero, J., Castander, F. J., Cavuoti, S., Cimatti, A., Cledassou, R., Congedo, G., Conversi, L., Copin, Y., Corcione, L., Courbin, F., Cropper, M., Da Silva, A., Degaudenzi, H., Dinis, J., Douspis, M., Dubath, F., Duncan, C. A. J., Dupac, X., Dusini, S., Farrens, S., Ferriol, S., Frailis, M., Franceschi, E., Franzetti, P., Galeotta, S., Garilli, B., Gillis, B., Giocoli, C., Grazian, A., Grupp, F., Haugan, S. V. H., Hoekstra, H., Holmes, W., Hormuth, F., Hornstrup, A., Hudelot, P., Jahnke, K., Kermiche, S., Kiessling, A., Kitching, T., Kohley, R., Kunz, M., Kurki-Suonio, H., Ligori, S., Lilje, P. B., Lloro, I., Mansutti, O., Marggraf, O., Markovic, K., Marulli, F., Massey, R., McCracken, H. J., Medinaceli, E., Melchior, M., Meneghetti, M., Meylan, G., Moresco, M., Moscardini, L., Munari, E., Niemi, S. M., Padilla, C., Paltani, S., Pasian, F., Pedersen, K., Percival, W. J., Polenta, G., Poncet, M., Popa, L., Pozzetti, L., Raison, F., Rebolo, R., Renzi, A., Rhodes, J., Riccio, G., Romelli, E., Rossetti, E., Saglia, R., Sapone, D., Sartoris, B., Schneider, P., Secroun, A., Seidel, G., Sirignano, C., Sirri, G., Skottfelt, J., Starck, J.-L., Tallada-Crespí, P., Taylor, A. N., Tereno, I., Toledo-Moreo, R., Tutusaus, I., Valenziano, L., Vassallo, T., Wang, Y., Weller, J., Zacchei, A., Zamorani, G., Zoubian, J., Andreon, S., Bardelli, S., Boucaud, A., Colodro-Conde, C., Di Ferdinando, D., Graciá-Carpio, J., Lindholm, V., Mauri, N., Mei, S., Neissner, C., Scottez, V., Tramacere, A., Zucca, E., Baccigalupi, C., Balaguera-Antolínez, A., Ballardini, M., Bernardeau, F., Biviano, A., Borgani, S., Borlaff, A. S., Burigana, C., Cabanac, R., Cappi, A., Carvalho, C. S., Casas, S., Castignani, G., Cooray, A. R., Coupon, J., Courtois, H. M., Cucciati, O., Davini, S., De Lucia, G., Desprez, G., Escartin, J. A., Escoffier, S., Farina, M., Ganga, K., Garcia-Bellido, J., George, K., Gozaliasl, G., Hildebrandt, H., Hook, I., Ilbert, O., Ilić, S., Joachimi, B., Kansal, V., Keihanen, E., Kirkpatrick, C. C., Loureiro, A., Macias-Perez, J., Magliocchetti, M., Mainetti, G., Maoli, R., Marcin, S., Martinelli, M., Martinet, N., Matthew, S., Maturi, M., Metcalf, R. B., Monaco, P., Morgante, G., Nadathur, S., Nucita, A. A., Patrizii, L., Popa, V., Porciani, C., Potter, D., Pourtsidou, A., Pöntinen, M., Reimberg, P., Sánchez, A. G., Sakr, Z., Schirmer, M., Sereno, M., Stadel, J., Teyssier, R., Valieri, C., Valiviita, J., van Mierlo, S. E., Veropalumbo, A., Viel, M., Weaver, J. R., and Scott, D.

Abstract

The European Space Agency's Euclid mission will provide high-quality imaging for about 1.5 billion galaxies. A software pipeline to automatically process and analyse such a huge amount of data in real time is being developed by the Science Ground Segment of the Euclid Consortium; this pipeline will include a model-fitting algorithm, which will provide photometric and morphological estimates of paramount importance for the core science goals of the mission and for legacy science. The Euclid Morphology Challenge is a comparative investigation of the performance of five model-fitting software packages on simulated Euclid data, aimed at providing the baseline to identify the best-suited algorithm to be implemented in the pipeline. In this paper we describe the simulated dataset, and we discuss the photometry results. A companion paper is focussed on the structural and morphological estimates. We created mock Euclid images simulating five fields of view of 0.48 deg2 each in the IE band of the VIS instrument, containing a total of about one and a half million galaxies (of which 350 000 have a nominal signal-to-noise ratio above 5), each with three realisations of galaxy profiles (single and double Sérsic, and 'realistic' profiles obtained with a neural network); for one of the fields in the double Sérsic realisation, we also simulated images for the three near-infrared YE, JE, and HE bands of the NISP-P instrument, and five Rubin/LSST optical complementary bands (u, g, r, i, and z), which together form a typical dataset for an Euclid observation. The images were simulated at the expected Euclid Wide Survey depths. To analyse the results, we created diagnostic plots and defined metrics to take into account the completeness of the provided catalogues, as well as the median biases, dispersions, and outlier frac

275. Cosmic strings with junctions : dynamics and cosmological implications

Author

Pourtsidou, Alkistis and Pourtsidou, Alkistis

Abstract

Cosmic strings are linear concentrations of energy that may have been formed after cosmological phase transitions in the early universe. Cosmic superstrings are analogous objects arising in string theory, and in particular in models of brane inflation. The latter possess two particular features, which differentiate them from the ordinary cosmic strings: a reduced intercommuting probability, and the ability to form junctions. This thesis is concerned with the dynamics and cosmological implications of cosmic strings and superstrings with junctions. In Chapter1, we give a brief introduction to the standard Big Bang model and t he inflationary paradigm. W e also discuss cosmic string formation after the spontaneous breaking of an Abelian U (I) gauge symmetry in the early Universe. In Chapter 2, we present an overview of cosmic string dynamics using the Nambu-Goto method. We discuss the properties of individual cosmic string segments and loops, as well as network evolution in an expanding Universe. We also introduce cosmic superstrings, and review the Nambu-Goto approach to study the evolution of junctions and the kinematic constraints that govern their formation. We conclude with the study of junctions in an expanding spacetime and present an exact solution for a closed loop of three strings and two junctions in a de Sitter Universe. In Chapter3, we compare the two different approaches developed to study the dynamics of strings with junctions. We first extensively study the dynamics and stability of a cosmic string loop with junctions using the modified Nambu-Goto approach. Comparing our results with a field theory model that permits junctions we find very good agreement. The Nambu-Goto method is once again confirmed to be a good approximation for studying cosmic string configurations. In Chapter4, we review the observational signatures of cosmic strings. More specifically, we concentrate on their gravitational effects, discussing results and constraints from lensing, g

276. Cosmic strings with junctions : dynamics and cosmological implications

Author

Pourtsidou, Alkistis and Pourtsidou, Alkistis

Abstract

Cosmic strings are linear concentrations of energy that may have been formed after cosmological phase transitions in the early universe. Cosmic superstrings are analogous objects arising in string theory, and in particular in models of brane inflation. The latter possess two particular features, which differentiate them from the ordinary cosmic strings: a reduced intercommuting probability, and the ability to form junctions. This thesis is concerned with the dynamics and cosmological implications of cosmic strings and superstrings with junctions. In Chapter1, we give a brief introduction to the standard Big Bang model and t he inflationary paradigm. W e also discuss cosmic string formation after the spontaneous breaking of an Abelian U (I) gauge symmetry in the early Universe. In Chapter 2, we present an overview of cosmic string dynamics using the Nambu-Goto method. We discuss the properties of individual cosmic string segments and loops, as well as network evolution in an expanding Universe. We also introduce cosmic superstrings, and review the Nambu-Goto approach to study the evolution of junctions and the kinematic constraints that govern their formation. We conclude with the study of junctions in an expanding spacetime and present an exact solution for a closed loop of three strings and two junctions in a de Sitter Universe. In Chapter3, we compare the two different approaches developed to study the dynamics of strings with junctions. We first extensively study the dynamics and stability of a cosmic string loop with junctions using the modified Nambu-Goto approach. Comparing our results with a field theory model that permits junctions we find very good agreement. The Nambu-Goto method is once again confirmed to be a good approximation for studying cosmic string configurations. In Chapter4, we review the observational signatures of cosmic strings. More specifically, we concentrate on their gravitational effects, discussing results and constraints from lensing, g

277. Update on the BINGO 21cm intensity mapping experiment

Author

Augé, Etienne, Dumarchez, Jacques, Trân Thanh Vân, Jean, Battye, Richard, Browne, Ian, Chen, Tianyue, Dickinson, Clive, Harper, Stuart, Olivari, Lucas, Peel, Michael, Remazeilles, Mathieu, Roychowdhury, Sambit, Wilkinson, Peter, Abdalla, Elcio, Abramo, Raul, Ferreira, Elisa, Wuensche, Alex, Vilella, Thyrso, Caldas, Manuel, Tancredi, Gonzalo, Refregier, Alexandre, Monstein, Christian, Abdalla, Filipe, Pourtsidou, Alkistis, Maffei, Bruno, Pisano, Giampaolo, Ma, Yin-Zhe, Augé, Etienne, Dumarchez, Jacques, Trân Thanh Vân, Jean, Battye, Richard, Browne, Ian, Chen, Tianyue, Dickinson, Clive, Harper, Stuart, Olivari, Lucas, Peel, Michael, Remazeilles, Mathieu, Roychowdhury, Sambit, Wilkinson, Peter, Abdalla, Elcio, Abramo, Raul, Ferreira, Elisa, Wuensche, Alex, Vilella, Thyrso, Caldas, Manuel, Tancredi, Gonzalo, Refregier, Alexandre, Monstein, Christian, Abdalla, Filipe, Pourtsidou, Alkistis, Maffei, Bruno, Pisano, Giampaolo, and Ma, Yin-Zhe

Abstract

1cm intensity mapping is a novel approach aimed at measuring the power spectrum of density fluctuations and deducing cosmological information, notably from the Baryonic Acoustic Oscillations (BAO). We give an update on the progress of BAO from Integrated Neutral Gas Observations (BINGO) which is a single dish intensity mapping project. First we explain the basic ideas behind intensity mapping concept before updating the instrument design for BINGO. We also outline the survey we plan to make and its projected science output including estimates of cosmological parameters.

278. Euclid preparation

Author

Pocino, A., Tutusaus, I., Castander, F. J., Fosalba, P., Crocce, M., Porredon, A., Camera, S., Cardone, V., Casas, S., Kitching, T., Lacasa, F., Martinelli, M., Pourtsidou, A., Sakr, Z., Andreon, S., Auricchio, N., Baccigalupi, C., Balaguera-Antolínez, A., Baldi, M., Balestra, A., Bardelli, S., Bender, R., Biviano, A., Bodendorf, C., Bonino, D., Boucaud, A., Bozzo, E., Branchini, E., Brescia, M., Brinchmann, J., Burigana, C., Cabanac, R., Capobianco, V., Cappi, A., Carvalho, C. S., Castellano, M., Castignani, G., Cavuoti, S., Cimatti, A., Cledassou, R., Colodro-Conde, C., Congedo, G., Conselice, C. J., Conversi, L., Copin, Y., Corcione, L., Costille, A., Coupon, J., Courtois, H. M., Cropper, M., Cuby, J.-G., Da Silva, A., de la Torre, S., Di Ferdinando, D., Dubath, F., Duncan, C., Dupac, X., Dusini, S., Farrens, S., Ferreira, P. G., Ferrero, I., Finelli, F., Fotopoulou, S., Frailis, M., Franceschi, E., Galeotta, S., Garilli, B., Gillard, W., Gillis, B., Giocoli, C., Gozaliasl, G., Graciá-Carpio, J., Grupp, F., Guzzo, L., Holmes, W., Hormuth, F., Jahnke, K., Keihanen, E., Kermiche, S., Kiessling, A., Kirkpatrick, C. C., Kunz, M., Kurki-Suonio, H., Ligori, S., Lilje, P. B., Lloro, I., Maino, D., Maiorano, E., Mansutti, O., Marggraf, O., Martinet, N., Marulli, F., Massey, R., Maurogordato, S., Medinaceli, E., Mei, S., Meneghetti, M., Benton Metcalf, R., Meylan, G., Moresco, M., Morin, B., Moscardini, L., Munari, E., Nakajima, R., Neissner, C., Nichol, R. C., Niemi, S., Nightingale, J., Padilla, C., Paltani, S., Pasian, F., Patrizii, L., Pedersen, K., Percival, W. J., Pettorino, V., Pires, S., Polenta, G., Poncet, M., Popa, L., Potter, D., Pozzetti, L., Raison, F., Renzi, A., Rhodes, J., Riccio, G., Romelli, E., Roncarelli, M., Rossetti, E., Saglia, R., Sánchez, A. G., Sapone, D., Scaramella, R., Schneider, P., Scottez, V., Secroun, A., Seidel, G., Serrano, S., Sirignano, C., Sirri, G., Stanco, L., Sureau, F., Taylor, A. N., Tenti, M., Tereno, I., Teyssier, R., Toledo-Moreo, R., Tramacere, A., Valentijn, E. A., Valenziano, L., Valiviita, J., Vassallo, T., Viel, M., Wang, Y., Welikala, N., Whittaker, L., Zacchei, A., Zamorani, G., Zoubian, J., and Zucca, E.

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279. Euclid preparation

Author

Blanchard, A., Camera, S., Carbone, C., Cardone, V. F., Casas, S., Clesse, S., Ilić, S., Kilbinger, M., Kitching, T., Kunz, M., Lacasa, F., Linder, E., Majerotto, E., Markovič, K., Martinelli, M., Pettorino, V., Pourtsidou, A., Sakr, Z., Sánchez, A. G., Sapone, D., Tutusaus, I., Yahia-Cherif, S., Yankelevich, V., Andreon, S., Aussel, H., Balaguera-Antolínez, A., Baldi, M., Bardelli, S., Bender, R., Biviano, A., Bonino, D., Boucaud, A., Bozzo, E., Branchini, E., Brau-Nogue, S., Brescia, M., Brinchmann, J., Burigana, C., Cabanac, R., Capobianco, V., Cappi, A., Carretero, J., Carvalho, C. S., Casas, R., Castander, F. J., Castellano, M., Cavuoti, S., Cimatti, A., Cledassou, R., Colodro-Conde, C., Congedo, G., Conselice, C. J., Conversi, L., Copin, Y., Corcione, L., Coupon, J., Courtois, H. M., Cropper, M., Da Silva, A., de la Torre, S., Di Ferdinando, D., Dubath, F., Ducret, F., Duncan, C. A. J., Dupac, X., Dusini, S., Fabbian, G., Fabricius, M., Farrens, S., Fosalba, P., Fotopoulou, S., Fourmanoit, N., Frailis, M., Franceschi, E., Franzetti, P., Fumana, M., Galeotta, S., Gillard, W., Gillis, B., Giocoli, C., Gómez-Alvarez, P., Graciá-Carpio, J., Grupp, F., Guzzo, L., Hoekstra, H., Hormuth, F., Israel, H., Jahnke, K., Keihanen, E., Kermiche, S., Kirkpatrick, C. C., Kohley, R., Kubik, B., Kurki-Suonio, H., Ligori, S., Lilje, P. B., Lloro, I., Maino, D., Maiorano, E., Marggraf, O., Martinet, N., Marulli, F., Massey, R., Medinaceli, E., Mei, S., Mellier, Y., Metcalf, B., Metge, J. J., Meylan, G., Moresco, M., Moscardini, L., Munari, E., Nichol, R. C., Niemi, S., Nucita, A. A., Padilla, C., Paltani, S., Pasian, F., Percival, W. J., Pires, S., Polenta, G., Poncet, M., Pozzetti, L., Racca, G. D., Raison, F., Renzi, A., Rhodes, J., Romelli, E., Roncarelli, M., Rossetti, E., Saglia, R., Schneider, P., Scottez, V., Secroun, A., Sirri, G., Stanco, L., Starck, J.-L., Sureau, F., Tallada-Crespí, P., Tavagnacco, D., Taylor, A. N., Tenti, M., Tereno, I., Toledo-Moreo, R., Torradeflot, F., Valenziano, L., Vassallo, T., Verdoes Kleijn, G. A., Viel, M., Wang, Y., Zacchei, A., Zoubian, J., and Zucca, E.

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280. Synergies between 21cm & optical surveys for probing large scale cosmic structure

Author

Cunnington, Steve D., Bacon, David James, Bruni, Marco, and Pourtsidou, Alkistis

Subjects
523.1
Abstract

We are currently living through an era of precision cosmology where we have gathered a substantial amount of data with the aim of understanding our Universe. However, our current understanding is far from complete as our most successful cosmological model relies on the Universe’s energy-matter content being vastly dominated by components that are not yet detected and not currently compatible with our wider general model of physics. This leaves plenty more investigation to be done and new techniques for probing our Universe are highly sought after. Mapping unresolved neutral hydrogen within galaxies is one of these novel techniques and has been gaining momentum over the last decade. By using the 21 cm signal from neutral hydrogen, which traces the underlying large scale cosmic structure, we can map and statistically analyse 3D density distributions and compare these to theoretical models. I provide a detailed introduction to this novel HI intensity mapping technique in Chapter 2. This thesis also explores what gains can be made by combining HI intensity mapping data with more conventional optical galaxy redshift surveys. There are many reasons why a cross correlation such as this will be beneficial. While the intensity mapping technique is developed and refined, optical data can boost the inherently weak HI signal allowing detection and a deeper understanding of the intensity mapping process. Also in the future, when we have dedicated intensity mapping instruments gathering data, cross-correlations will see reductions in the different systematics which could otherwise dominate the uncertainty in any auto-correlations. With the use of computer simulations, I look to forecast benefits to be gained from this synergy and in Chapter 3 I provide an example of how HI intensity maps can be used to constrain photometric redshifts on optical imaging surveys. The largest problem preventing the success of HI intensity mapping comes from 21 cm foregrounds whose signals dominate by several orders of magnitude over the weak HI cosmological signal. While we have several methods for cleaning these foregrounds, understanding the impact these reconstructions have on the data is crucial and is the key theme in Chapters 4 and 5. Again using computer simulations of cosmological HI intensity mapping signals and their foreground contamination, I show how foregrounds can be removed and with some additional treatment, successfully used in cross-correlation with an optical photometric galaxy survey. This indicates a promising future for cosmology and suggests the next-generation of optical telescopes such as LSST and Euclid, should benefit hugely from synergies with intensity mapping data provided by a next-generation radio telescope such as the SKA.

Published
2019

281. Euclid: Forecasts for k-cut 3×2 Point Statistics

Author

Peter L. Taylor, T. Kitching, V. F. Cardone, A. Ferté, E. M. Huff, F. Bernardeau, J. Rhodes, A. C. Deshpande, I. Tutusaus, Alkistis Pourtsidou, S. Camera, C. Carbone, S. Casas, M. Martinelli, V. Pettorino, Z. Sakr, D. Sapone, V. Yankelevich, N. Auricchio, A. Balestra, C. Bodendorf, D. Bonino, A. Boucaud, Enzo Branchini, M. Brescia, V. Capobianco, J. Carretero, M. Castellano, S. Cavuoti, A. Cimatti, R. Cledassou, G. Congedo, L. Conversi, L. Corcione, Mark Cropper, E. Franceschi, B. Garilli, B. Gillis, C. Giocoli, L. Guzzo, S. V. H. Haugan, W. Holmes, F. Hormuth, Knud Jahnke, S. Kermiche, M. Kilbinger, M. Kunz, H. Kurki-Suonio, S. Ligori, Per B. Lilje, I. Lloro, O. Marggraf, K. Markovic, R. Massey, S. Mei, E. Medinaceli, M. Meneghetti, G. Meylan, M. Moresco, B. Morin, Lauro Moscardini, S. Niemi, C. Padilla, F. Pasian, S. Paltani, K. Pedersen, S. Pires, Will J. Percival, G. Polenta, M. Poncet, L. Popa, F. Raison, M. Roncarelli, E. Rossetti, R. Saglia, Peter Schneider, A. Secroun, G. Seidel, S. Serrano, C. Sirignano, G. Sirri, F. Sureau, P. Tallada Crespí, D. Tavagnacco, A. N. Taylor, H. I. Teplitz, I. Tereno, R. Toledo-Moreo, E. A. Valentijn, L. Valenziano, T. Vassallo, Yun Wang, Jochen Weller, A. Zacchei, and J. Zoubian

Subjects
Astronomy, QB1-991, Astrophysics, QB460-466
Published
2021
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282. Assessing non-linear models for galaxy clustering I: unbiased growth forecasts from multipole expansion

Author

Katarina Markovic, Benjamin Bose, and Alkistis Pourtsidou

Subjects
Astronomy, QB1-991, Astrophysics, QB460-466
Abstract

We assess the performance of the Taruya, Nishimichi and Saito (TNS) model for the halo redshift space power spectrum, focusing on utilising mildly non-linear scales to constrain the growth rate of structure f. Using simulations with volume and number density typical of forthcoming Stage IV galaxy surveys, we determine ranges of validity for the model at redshifts z = 0.5 and z = 1. We proceed to perform a Bayesian MCMC analysis utilising the monopole, quadrupole, and hexadecapole spectra, followed by an exploratory Fisher matrix analysis. As previously noted in other forecasts as well as in real data analyses, we find that including the hexadecapole can significantly improve the constraints. However, a restricted range of scales is required for the hexadecapole in order for the growth parameter estimation to remain unbiased, limiting the improvement. We consistently quantify these effects by employing the multipole expansion formalism in both our Fisher and MCMC forecasts.

Published
2019
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283. [Untitled]

Author

Achúcarro, A., Silvestri, A., Martinelli, M., Pourtsidou, A., Eliel, E.R., Hoekstra, H., Schalm, K.E., and Leiden University

Subjects
Gravitational-waves, Bayesian Statistical Analysis, Inflation, Cosmology
Abstract

The ultimate goal of cosmologists is to find a cosmological model able to explain the current observational data. In this sense, the Standard Cosmological model establishes that our universe is mainly composed of two unknown components: a type of matter that is known to only interact through gravitation, Cold Dark Matter, and a substance responsible for the current accelerated expansion of the universe that can be modelled by a cosmological constant. Still, this model, though successful, fails to answer hot-burning questions in the field. For this reason, theoretical cosmologists focus on developing further modifications of the model to test them against astrophysical data and check whether alternative scenarios can provide a better explanation of the observations.This thesis is dedicated to the Bayesian statistical analyses of extensions of the Standard Cosmological model using several astronomical data sets, and to the forecast of new observables and experiments. The first part focuses on data science and inflation, and it aims to constrain inflationary models using advanced inference techniques. The second part of the thesis is dedicated to the novel concept of cross-correlations of gravitational-wave physics and large scale structure observables. The third part of this thesis is dedicated to the incoming ESA Euclid satellite, and in particular, it focuses on a crucial data science analysis software for the mission: the code “Cosmological Likelihood for Observables in Euclid”, also known as CLOE.

Published
2022

284. Playing dice with the universe: Bayesian statistical analyses of cosmological models and new observables

Author

Cañas Herrera, G., Achúcarro, A., Silvestri, A., Martinelli, M., Pourtsidou, A., Eliel, E.R., Hoekstra, H., Schalm, K.E., and Leiden University

Subjects
Gravitational-waves, Bayesian Statistical Analysis, Inflation, Cosmology
Abstract

The ultimate goal of cosmologists is to find a cosmological model able to explain the current observational data. In this sense, the Standard Cosmological model establishes that our universe is mainly composed of two unknown components: a type of matter that is known to only interact through gravitation, Cold Dark Matter, and a substance responsible for the current accelerated expansion of the universe that can be modelled by a cosmological constant. Still, this model, though successful, fails to answer hot-burning questions in the field. For this reason, theoretical cosmologists focus on developing further modifications of the model to test them against astrophysical data and check whether alternative scenarios can provide a better explanation of the observations.This thesis is dedicated to the Bayesian statistical analyses of extensions of the Standard Cosmological model using several astronomical data sets, and to the forecast of new observables and experiments. The first part focuses on data science and inflation, and it aims to constrain inflationary models using advanced inference techniques. The second part of the thesis is dedicated to the novel concept of cross-correlations of gravitational-wave physics and large scale structure observables. The third part of this thesis is dedicated to the incoming ESA Euclid satellite, and in particular, it focuses on a crucial data science analysis software for the mission: the code “Cosmological Likelihood for Observables in Euclid”, also known as CLOE.

Published
2022

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