459 results on '"Pisin Chen"'
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2. Particle production by a relativistic semitransparent mirror of finite size and thickness
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Kuan-Nan Lin and Pisin Chen
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Astrophysics ,QB460-466 ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract Production of massless scalar particles by a relativistic semitransparent mirror of finite transverse size and longitudinal thickness in (1+3)D flat spacetime is studied. The derived particle spectrum formula is applied to two specific trajectories. One is the gravitational collapse trajectory invoked in (1+1)D perfectly reflecting moving mirror literature to mimic Hawking radiation, and the other is the plasma mirror trajectory proposed to be realizable in future experiments. It is found that the finiteness of the transverse size leads to diffraction, while the nontrivial thickness amplifies the production rate. We also estimated the particle yield as $$\sim 3000$$ ∼ 3000 in a 20-day data acquisition based on the parameters invoked in the proposed AnaBHEL experiment.
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- 2024
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3. Tunneling between Multiple Histories as a Solution to the Information Loss Paradox
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Pisin Chen, Misao Sasaki, Dong-han Yeom, and Junggi Yoon
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black hole ,Hawking evaporation ,information loss paradox ,entanglement entropy ,Euclidean path integral ,Page time ,Science ,Astrophysics ,QB460-466 ,Physics ,QC1-999 - Abstract
The information loss paradox associated with black hole Hawking evaporation is an unresolved problem in modern theoretical physics. In a recent brief essay, we revisited the evolution of the black hole entanglement entropy via the Euclidean path integral (EPI) of the quantum state and allow for the branching of semi-classical histories along the Lorentzian evolution. We posited that there exist at least two histories that contribute to EPI, where one is an information-losing history, while the other is an information-preserving one. At early times, the former dominates EPI, while at the late times, the latter becomes dominant. By doing so, we recovered the essence of the Page curve, and thus, the unitarity, albeit with the turning point, i.e., the Page time, much shifted toward the late time. In this full-length paper, we fill in the details of our arguments and calculations to strengthen our notion. One implication of this modified Page curve is that the entropy bound may thus be violated. We comment on the similarity and difference between our approach and that of the replica wormholes and the islands’ conjectures.
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- 2023
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4. Preface for Special Issue: Progress in Laser Accelerator and Future Prospects
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Toshiki Tajima and Pisin Chen
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n/a ,Applied optics. Photonics ,TA1501-1820 - Abstract
In early 2022, one of the authors (Professor T [...]
- Published
- 2023
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5. Modification to the Hawking temperature of a dynamical black hole by a flow-induced supertranslation
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Hsu-Wen Chiang, Yu-Hsien Kung, and Pisin Chen
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Black Holes ,Classical Theories of Gravity ,Space-Time Symmetries ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract One interesting proposal to solve the black hole information loss paradox without modifying either general relativity or quantum field theory, is the soft hair, a diffeomorphism charge that records the anisotropic radiation in the asymptotic region. This proposal, however, has been challenged, given that away from the source the soft hair behaves as a coordinate transformation that forms an Abelian group, thus unable to store any information. To maintain the spirit of the soft hair but circumvent these obstacles, we consider Hawking radiation as a probe sensitive to the entire history of the black hole evaporation, where the soft hairs on the horizon are induced by the absorption of a null anisotropic flow, generalizing the shock wave considered in [1, 2]. To do so we introduce two different time-dependent extensions of the diffeomorphism associated with the soft hair, where one is the backreaction of the anisotropic null flow, and the other is a coordinate transformation that produces the Unruh effect and a Doppler shift to the Hawking spectrum. Together, they form an exact BMS charge generator on the entire manifold that allows the nonperturbative analysis of the black hole horizon, whose surface gravity, i.e. the Hawking temperature, is found to be modified. The modification depends on an exponential average of the anisotropy of the null flow with a decay rate of 4M, suggesting the emergence of a new 2-D degree of freedom on the horizon, which could be a way out of the information loss paradox.
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- 2020
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6. Eddington-inspired-Born–Infeld tensorial instabilities neutralized in a quantum approach
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Imanol Albarran, Mariam Bouhmadi-López, Che-Yu Chen, and Pisin Chen
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Astrophysics ,QB460-466 ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract The recent direct detection of gravitational waves has highlighted the huge importance of the tensorial modes in any extended gravitational theory. One of the most appealing approaches to extend gravity beyond general relativity is the Eddington-inspired-Born–Infeld gravity which is formulated within the Palatini approach. This theory can avoid the Big Bang singularity in the physical metric although a Big Bang intrinsic to the affine connection is still there, which in addition couples to the tensorial sector and might jeopardize the viability of the model. In this paper, we suggest that a quantum treatment of the affine connection, or equivalently of its compatible metric, is able to rescue the model. We carry out such an analysis and conclude that from a quantum point of view such a Big Bang is unharmful. We expect therefore that the induced tensorial instability, caused by the Big Bang intrinsic to the affine connection, can be neutralized at the quantum level.
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- 2020
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7. AnaBHEL (Analog Black Hole Evaporation via Lasers) Experiment: Concept, Design, and Status
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Pisin Chen, Gerard Mourou, Marc Besancon, Yuji Fukuda, Jean-Francois Glicenstein, Jiwoo Nam, Ching-En Lin, Kuan-Nan Lin, Shu-Xiao Liu, Yung-Kun Liu, Masaki Kando, Kotaro Kondo, Stathes Paganis, Alexander Pirozhkov, Hideaki Takabe, Boris Tuchming, Wei-Po Wang, Naoki Watamura, Jonathan Wheeler, and Hsin-Yeh Wu
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AnaBHEL (Analog Black Hole Evaporation via Lasers) ,Hawking radiation ,information loss paradox ,relativistic flying mirror ,Applied optics. Photonics ,TA1501-1820 - Abstract
Accelerating relativistic mirrors have long been recognized as viable settings where the physics mimic those of the black hole Hawking radiation. In 2017, Chen and Mourou proposed a novel method to realize such a system by traversing an ultra-intense laser through a plasma target with a decreasing density. An international AnaBHEL (Analog Black Hole Evaporation via Lasers) collaboration was formed with the objectives of observing the analog Hawking radiation, shedding light on the information loss paradox. To reach these goals, we plan to first verify the dynamics of the flying plasma mirror and characterize the correspondence between the plasma density gradient and the trajectory of the accelerating plasma mirror. We will then attempt to detect the analog Hawking radiation photons and measure the entanglement between the Hawking photons and their “partner particles”. In this paper, we describe our vision and strategy of AnaBHEL using the Apollon laser as a reference, and we report on the progress of our R&D concerning the key components in this experiment, including the supersonic gas jet with a graded density profile, and the superconducting nanowire single-photon Hawking detector. In parallel to these hardware efforts, we performed computer simulations to estimate the potential backgrounds, and derived analytic expressions for modifications to the blackbody spectrum of the Hawking radiation for a perfectly reflecting point mirror, due to the semi-transparency and finite-size effects specific to flying plasma mirrors. Based on this more realistic radiation spectrum, we estimate the Hawking photon yield to guide the design of the AnaBHEL experiment, which appears to be achievable.
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- 2022
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8. Generalized Holographic Principle, Gauge Invariance and the Emergence of Gravity à la Wilczek
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Andrea Addazi, Pisin Chen, Filippo Fabrocini, Chris Fields, Enrico Greco, Matteo Lulli, Antonino Marcianò, and Roman Pasechnik
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Wilczek gravity ,black hole information loss problem ,emergent gravity ,gauge invariance ,holographic principle ,Astronomy ,QB1-991 ,Geophysics. Cosmic physics ,QC801-809 - Abstract
We show that a generalized version of the holographic principle can be derived from the Hamiltonian description of information flow within a quantum system that maintains a separable state. We then show that this generalized holographic principle entails a general principle of gauge invariance. When this is realized in an ambient Lorentzian space-time, gauge invariance under the Poincaré group is immediately achieved. We apply this pathway to retrieve the action of gravity. The latter is cast à la Wilczek through a similar formulation derived by MacDowell and Mansouri, which involves the representation theory of the Lie groups SO(3,2) and SO(4,1).
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- 2021
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9. Primordial bouncing cosmology in the Deser-Woodard nonlocal gravity
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Che-Yu Chen, Pisin Chen, and Sohyun Park
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Physics ,QC1-999 - Abstract
The Deser-Woodard (DW) nonlocal gravity model has been proposed in order to describe the late-time acceleration of the universe without introducing dark energy. In this paper we focus, however, on the early stage of the universe and demonstrate how a primordial bounce in the vacuum spacetime can be realized in the framework of the DW nonlocal model. We reconstruct the nonlocal distortion function, which encodes all the modifications to the Einstein-Hilbert action, in order to generate bouncing solutions to solve the initial singularity problem. We show that the initial conditions can be chosen in such a way that the distortion function and its first order derivative approach zero after the bounce and the standard cosmological solution described by general relativity is recovered afterwards. We also study the evolution of anisotropies near the bounce. It turns out that the shear density defined by the anisotropy grows towards the bounce, but due to the presence of nonlocal effects, it grows in a milder manner compared with that in Einstein gravity. Keywords: Modified theories of gravity, Bouncing cosmology, Nonlocal gravity
- Published
- 2019
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10. Dark energy induced anisotropy in cosmic expansion
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Chien-Ting Chen and Pisin Chen
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Astrophysics ,QB460-466 ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract In order to understand the nature of the accelerating expansion of the late-time universe, it is important to experimentally determine whether dark energy is a cosmological constant or dynamical in nature. If dark energy already exists prior to inflation, which is a reasonable assumption, then one expects that a dynamical dark energy would leave some footprint in the anisotropy of the late-time accelerated expansion. To demonstrate the viability of this notion, we invoke the quintessence field with the exponential potential as one of the simplest dynamical dark energy models allowed by observations. We investigate the effects of its quantum fluctuations (the physical origin of the perturbation being isocurvature) generated during inflation and having fully positive correlation with the primordial curvature perturbations, and estimate the anisotropy of the cosmic expansion so induced. We show that the primordial amplitude of quantum fluctuations of quintessence field $$ \delta \phi _{\text {P}} $$ δϕP can be related to the tensor-to-scalar ratio r, and we calculate the perturbed luminosity distance to first order and the associated luminosity distance power spectrum, which is an estimator of anisotropy of late-time accelerated expansion. We find that the gravitational potential at large scales and late times is less decayed in QCDM compared to that in $$ \Lambda $$ Λ CDM so that the smaller the redshift and multipole, the more relative deficit of power in QCDM. Our results of luminosity distance power spectrum also show the similar conclusions of suppression as that of the previous investigation regarding the effect of quantum fluctuations of quintessence field on the CMB temperature anisotropies.
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- 2019
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11. Hawking radiation as instantons
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Pisin Chen, Misao Sasaki, and Dong-han Yeom
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Astrophysics ,QB460-466 ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract There have been various interpretations of Hawking radiation proposed based on the perturbative approach, and all have confirmed Hawking’s original finding. One major conceptual challenge of Hawking evaporation is the associated black hole information loss paradox, which remains unresolved. A key factor to the issue is the end-stage of the black hole evaporation. Unfortunately by then the evaporation process becomes non-perturbative. Aspired to provide a tool for the eventual solution to this problem, here we introduce a new interpretation of Hawking radiation as the tunneling of instantons. We study instantons of a massless scalar field in Einstein gravity. We consider a complex-valued instanton that connects an initial pure black hole state to a black hole with a scalar field that represents the Hawking radiation at future null infinity, where its action depends only on the areal entropy difference. By comparing it with several independent approaches to Hawking radiation in the perturbative limit, we conclude that Hawking radiation may indeed be described by a family of instantons. Since the instanton approach can describe non-perturbative processes, we hope that our new interpretation and holistic method may shed lights on the information loss problem.
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- 2019
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12. Emergent inflation from a Nambu–Jona-Lasinio mechanism in gravity with non-dynamical torsion
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Andrea Addazi, Pisin Chen, and Antonino Marcianò
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Astrophysics ,QB460-466 ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract We discuss how inflation can emerge from a four-fermion interaction induced by torsion. Inflation can arise from coupling torsion to Standard Model fermions, without any need of introducing new scalar particles beyond the Standard Model. Within this picture, the inflaton field can be a composite field of the SM-particles and arises from a Nambu–Jona-Lasinio mechanism in curved space-time, non-minimally coupled with the Ricci scalar. The model we specify predicts small value of the r-parameter, namely $$r\sim 10^{-4} \div 10^{-2}$$ r∼10-4÷10-2 , which nonetheless would be detectable by the next generation of experiments, including BICEP 3 and the AliCPT projects.
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- 2019
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13. Probing Palatini-type gravity theories through gravitational wave detections via quasinormal modes
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Che-Yu Chen, Mariam Bouhmadi-López, and Pisin Chen
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Astrophysics ,QB460-466 ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract The possibility of testing gravity theories with the help of gravitational wave detections has become an interesting arena of recent research. In this paper, we follow this direction by investigating the quasinormal modes (QNMs) of the axial perturbations for charged black holes in the Palatini-type theories of gravity, specifically (1) the Palatini f(R) gravity coupled with Born-Infeld nonlinear electrodynamics and (2) the Eddington-inspired-Born-Infeld gravity (EiBI) coupled with Maxwell electromagnetic fields. The coupled master equations describing perturbations of charged black holes in these theories are obtained with the tetrad formalism. By using the Wentzel-Kramers-Brillouin (WKB) method up to 6th order, we calculate the QNM frequencies of the EiBI charged black holes, the Einstein-Born-Infeld black holes, and the Born-Infeld charged black holes within the Palatini $$R+\alpha R^2$$ R+αR2 gravity. The QNM spectra of these black holes would deviate from those of the Reissner-Nordström black hole. In addition, we study the QNMs in the eikonal limit and find that for the axial perturbations of the EiBI charged black holes, the link between the eikonal QNMs and the unstable null circular orbit around the black hole is violated.
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- 2019
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14. Suppression of long-wavelength CMB spectrum from the no-boundary initial condition
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Pisin Chen, Yu-Hsiang Lin, and Dong-han Yeom
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Astrophysics ,QB460-466 ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract The lack of correlations at the long-wavelength scales of the cosmic microwave background spectrum is a long-standing puzzle and it persists in the latest Planck data. By considering the Hartle–Hawking no-boundary wave function as the initial condition of the inflationary universe, we propose that the power suppression can be the consequence of a massive inflaton, whose initial vacuum is the Euclidean instanton in a compact manifold. We calculate the primordial power spectrum of the perturbations, and find that as long as the scalar field is moderately massive, the power spectrum is suppressed at the long-wavelength scales.
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- 2018
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15. Why concave rather than convex inflaton potential?
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Pisin Chen and Dong-han Yeom
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Astrophysics ,QB460-466 ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract The Planck data on cosmic microwave background indicates that the Starobinsky-type model with concave inflation potential is favored over the convex-type chaotic inflation. Is there any reason for that? Here we argue that if our universe began with a Euclidean wormhole, then the Starobinsky-type inflation is probabilistically favored. It is known that for a more generic choice of parameters than that originally assumed by Hartle and Hawking, the Hartle–Hawking wave function is dominated by Euclidean wormholes, which can be interpreted as the creation of two classical universes from nothing. We show that only one end of the wormhole can be classicalized for a convex potential, while both ends can be classicalized for a concave potential. The latter is therefore more probable.
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- 2018
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16. Black hole solutions in mimetic Born-Infeld gravity
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Che-Yu Chen, Mariam Bouhmadi-López, and Pisin Chen
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Astrophysics ,QB460-466 ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract The vacuum, static, and spherically symmetric solutions in the mimetic Born-Infeld gravity are studied. The mimetic Born-Infeld gravity is a reformulation of the Eddington-inspired-Born-Infeld (EiBI) model under the mimetic approach. Due to the mimetic field, the theory contains non-trivial vacuum solutions different from those in Einstein gravity. We find that with the existence of the mimetic field, the spacelike singularity inside a Schwarzschild black hole could be altered to a lightlike singularity, even though the curvature invariants still diverge at the singularity. Furthermore, in this case, the maximal proper time for a timelike radially-infalling observer to reach the singularity is found to be infinite.
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- 2018
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17. Detection of Low-Energy X-rays Using YSO Scintillation Crystal Arrays for GRB Experiments
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Minbin Kim, Jakub Ripa, Il H. Park, Vitaly Bogomolov, Søren Brandt, Carl Budtz-Jørgensen, Alberto J. Castro-Tirado, Sheng-Hsiung Chang, Yenyun Chang, Chia Ray Chen, C.-W. Chen, Pisin Chen, Paul Connell, Chris Eyles, Georgii Gaikov, Gihan Hong, Jian Jung Huang, Ming-Huey Alfred Huang, Soomin Jeong, Jieun Kim, Jik Lee, Heuijin Lim, Chih-Yang Lin, Tsung-Che Liu, Jiwoo Nam, Mikhail Panasyuk, Vasily Petrov, Victor Reglero, Juana M. Rodrigo, Sergey Svertilov, Nikolay Vedenkin, Ming Zu Wang, and Ivan Yashin
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gamma-ray burst ,YSO ,UBAT ,UFFO ,Elementary particle physics ,QC793-793.5 - Abstract
We developed an X-ray detector using 36 arrays, each consisting of a 64-pixellated yttrium oxyorthosilicate (YSO) scintillation crystal and a 64-channel multi-anode photomultiplier tube. The X-ray detector was designed to detect X-rays with energies lower than 10 keV, primarily with the aim of localizing gamma-ray bursts (GRBs). YSO crystals have no intrinsic background, which is advantageous for increasing low-energy sensitivity. The fabricated detector was integrated into UBAT, the payload of the Ultra-Fast Flash Observatory (UFFO)/Lomonosov for GRB observation. The UFFO was successfully operated in space in a low-Earth orbit. In this paper, we present the responses of the X-ray detector of the UBAT engineering model identical to the flight model, using 241Am and 55Fe radioactive sources and an Amptek X-ray tube. We found that the X-ray detector can measure energies lower than 5 keV. As such, we expect YSO crystals to be good candidates for the X-ray detector materials for future GRB missions.
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- 2021
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18. Doomsdays in a modified theory of gravity: A classical and a quantum approach
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Imanol Albarran, Mariam Bouhmadi-López, Che-Yu Chen, and Pisin Chen
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Quantum cosmology ,Modified theories of gravity ,Dark energy doomsdays ,Palatini type of theories ,Physics ,QC1-999 - Abstract
By far cosmology is one of the most exciting subject to study, even more so with the current bulk of observations we have at hand. These observations might indicate different kinds of doomsdays, if dark energy follows certain patterns. Two of these doomsdays are the Little Rip (LR) and Little Sibling of the Big Rip (LSBR). In this work, aside from proving the unavoidability of the LR and LSBR in the Eddington-inspired-Born-Infeld (EiBI) scenario, we carry out a quantum analysis of the EiBI theory with a matter field, which, from a classical point of view would inevitably lead to a universe that ends with either LR or LSBR. Based on a modified Wheeler–DeWitt equation, we demonstrate that such fatal endings seems to be avoidable.
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- 2017
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19. Thermal activation of thin-shells in anti-de Sitter black hole spacetime
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Pisin Chen, Guillem Domènech, Misao Sasaki, and Dong-han Yeom
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Black Holes ,Nonperturbative Effects ,Models of Quantum Gravity ,Thermal Field Theory ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract We investigate thermal activation of thin-shells around anti-de Sitter black holes. Under the thin-shell approximation, we extensively study the parameter region that allows a bubble nucleation bounded by a thin-shell out of a thermal bath. We show that in general if one fixes the temperature outside the shell, one needs to consider the presence of a conical deficit inside the shell in the Euclidean manifold, due to the lack of solutions with a smooth manifold. We show that for a given set of theoretical parameters, i.e., vacuum and shell energy density, there is a finite range of black hole masses that allow this transition. Most interestingly, one of them describes the complete evaporation of the initial black hole.
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- 2017
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20. Phantom dark ghost in Einstein–Cartan gravity
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Yu-Chiao Chang, Mariam Bouhmadi-López, and Pisin Chen
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Dark Energy ,Dark Energy Model ,Cold Dark Matter ,Contortion Tensor ,Affine Connection ,Astrophysics ,QB460-466 ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract A class of dynamical dark energy models is constructed through an extended version of fermion fields corresponding to phantom dark ghost spinors, which are spin 1/2 with mass dimension 1. We find that if these spinors interact with torsion fields in a homogeneous and isotropic universe, then it does not imply any future dark energy singularity or any abrupt event, though the fermion has a negative kinetic energy. In fact, the equation of state of this dark energy model will asymptotically approach the value $$w=-1$$ w = - 1 from above without crossing the phantom divide and inducing therefore a de Sitter state. Consequently, we expect the model to be stable because no real phantom fields will be created. At late time, the torsion fields will vanish as the corresponding phantom dark ghost spinors dilute. As would be expected, intuitively, this result is unaffected by the presence of cold dark matter although the proof is not as straightforward as in general relativity.
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- 2017
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21. Quantum Power Distribution of Relativistic Acceleration Radiation: Classical Electrodynamic Analogies with Perfectly Reflecting Moving Mirrors
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Abay Zhakenuly, Maksat Temirkhan, Michael R. R. Good, and Pisin Chen
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quantum power distribution ,3 + 1-dimensions ,moving mirrors ,Mathematics ,QA1-939 - Abstract
We find the quantum power emitted and distribution in 3 + 1-dimensions of relativistic acceleration radiation using a single perfectly reflecting mirror via Lorentz invariance, demonstrating close analogies to point charge radiation in classical electrodynamics.
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- 2021
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22. Cold black holes in the Harlow–Hayden approach to firewalls
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Yen Chin Ong, Brett McInnes, and Pisin Chen
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Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Firewalls are controversial principally because they seem to imply departures from general relativistic expectations in regions of spacetime where the curvature need not be particularly large. One of the virtues of the Harlow–Hayden approach to the firewall paradox, concerning the time available for decoding of Hawking radiation emanating from charged AdS black holes, is precisely that it operates in the context of cold black holes, which are not strongly curved outside the event horizon. Here we clarify this point. The approach is based on ideas borrowed from applications of the AdS/CFT correspondence to the quark–gluon plasma. Firewalls aside, our work presents a detailed analysis of the thermodynamics and evolution of evaporating charged AdS black holes with flat event horizons. We show that, in one way or another, these black holes are always eventually destroyed in a time which, while long by normal standards, is short relative to the decoding time of Hawking radiation.
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- 2015
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23. The Mimetic Born-Infeld Gravity: The Primordial Cosmos and Spherically Symmetric Solutions
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Che-Yu Chen, Mariam Bouhmadi-López, and Pisin Chen
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modified theories of gravity ,spacetime singularities ,early universe ,black holes ,Astronomy ,QB1-991 - Abstract
The Eddington-inspired-Born-Infeld (EiBI) model is reformulated within the mimetic approach. In the presence of a mimetic field, the model contains non-trivial vacuum solutions. We study a realistic primordial vacuum universe and we prove the existence of regular solutions. Besides, the linear instabilities in the EiBI model are found to be avoidable for some bouncing solutions. For a vacuum, static and spherically symmetric geometry, a new branch of solutions in which the black hole singularity that is replaced with a lightlike singularity is found.
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- 2017
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24. Erratum: Particle-in-cell simulation of x-ray wakefield acceleration and betatron radiation in nanotubes [Phys. Rev. Accel. Beams 19, 101004 (2016)]
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Xiaomei Zhang, Toshiki Tajima, Deano Farinella, Youngmin Shin, Gerard Mourou, Jonathan Wheeler, Peter Taborek, Pisin Chen, Franklin Dollar, and Baifei Shen
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Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Published
- 2016
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25. Particle-in-cell simulation of x-ray wakefield acceleration and betatron radiation in nanotubes
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Xiaomei Zhang, Toshiki Tajima, Deano Farinella, Youngmin Shin, Gerard Mourou, Jonathan Wheeler, Peter Taborek, Pisin Chen, Franklin Dollar, and Baifei Shen
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Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Though wakefield acceleration in crystal channels has been previously proposed, x-ray wakefield acceleration has only recently become a realistic possibility since the invention of the single-cycled optical laser compression technique. We investigate the acceleration due to a wakefield induced by a coherent, ultrashort x-ray pulse guided by a nanoscale channel inside a solid material. By two-dimensional particle-in-cell computer simulations, we show that an acceleration gradient of TeV/cm is attainable. This is about 3 orders of magnitude stronger than that of the conventional plasma-based wakefield accelerations, which implies the possibility of an extremely compact scheme to attain ultrahigh energies. In addition to particle acceleration, this scheme can also induce the emission of high energy photons at ∼O(10–100) MeV. Our simulations confirm such high energy photon emissions, which is in contrast with that induced by the optical laser driven wakefield scheme. In addition to this, the significantly improved emittance of the energetic electrons has been discussed.
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- 2016
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26. A Principle Component Analysis of Galaxy Properties from a Large, Gas-Selected Sample
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Yu-Yen Chang, Rikon Chao, Wei-Hao Wang, and Pisin Chen
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Astronomy ,QB1-991 - Abstract
Disney et al. (2008) have found a striking correlation among global parameters of Hi-selected galaxies and concluded that this is in conflict with the CDM model. Considering the importance of the issue, we reinvestigate the problem using the principal component analysis on a fivefold larger sample and additional near-infrared data. We use databases from the Arecibo Legacy Fast Arecibo L-band Feed Array Survey for the gas properties, the Sloan Digital Sky Survey for the optical properties, and the Two Micron All Sky Survey for the near-infrared properties. We confirm that the parameters are indeed correlated where a single physical parameter can explain 83% of the variations. When color (g-i) is included, the first component still dominates but it develops a second principal component. In addition, the near-infrared color (i-J) shows an obvious second principal component that might provide evidence of the complex old star formation. Based on our data, we suggest that it is premature to pronounce the failure of the CDM model and it motivates more theoretical work.
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- 2012
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27. Everything about Gravity: Proceedings of the Second LeCosPA International Symposium
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Pisin Chen and Pisin Chen
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- 2016
28. BURSTT: Bustling Universe Radio Survey Telescope in Taiwan
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Hsiu-Hsien Lin, Kai-yang Lin, Chao-Te Li, Yao-Huan Tseng, Homin Jiang, Jen-Hung Wang, Jen-Chieh Cheng, Ue-Li Pen, Ming-Tang Chen, Pisin Chen, Yaocheng Chen, Tomotsugu Goto, Tetsuya Hashimoto, Yuh-Jing Hwang, Sun-Kun King, Derek Kubo, Chung-Yun Kuo, Adam Mills, Jiwoo Nam, Peter Oshiro, Chang-Shao Shen, Hsien-Chun Tseng, Shih-Hao Wang, Vigo Feng-Shun Wu, Geoffrey Bower, Shu-Hao Chang, Pai-An Chen, Ying-Chih Chen, Yi-Kuan Chiang, Anatoli Fedynitch, Nina Gusinskaia, Simon C.-C. Ho, Tiger Y.-Y. Hsiao, Chin-Ping Hu, Yau De Huang, José Miguel Jáuregui García, Seong Jin Kim, Cheng-Yu Kuo, Decmend Fang-Jie Ling, Alvina Y. L. On, Jeffrey B. Peterson, Bjorn Jasper R. Raquel, Shih-Chieh Su, Yuri Uno, Cossas K.-W. Wu, Shotaro Yamasaki, and Hong-Ming Zhu
- Subjects
High Energy Astrophysical Phenomena (astro-ph.HE) ,Space and Planetary Science ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics - Instrumentation and Methods for Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena ,Instrumentation and Methods for Astrophysics (astro-ph.IM) - Abstract
Fast Radio Bursts (FRBs) are bright millisecond-duration radio transients that appear about 1,000 times per day, all-sky, for a fluence threshold 5 Jy ms at 600 MHz. The FRB radio-emission physics and the compact objects involved in these events are subjects of intense active debate. To better constrain source models, the Bustling Universe Radio Survey Telescope in Taiwan (BURSTT) is optimized to discover and localize a large sample of rare, high-fluence, nearby FRBs. This is the population most amenable to multi-messenger, multi-wavelength follow-up, allowing deeper understanding of source mechanisms. BURSTT will provide horizon-to-horizon sky coverage with a half power field-of-view (FoV) of $\sim$10$^{4}$ deg$^{2}$, a 400 MHz effective bandwidth between 300-800 MHz, and sub-arcsecond localization, made possible using outrigger stations hundreds to thousands of km from the main array. Initially, BURSTT will employ 256 antennas. After tests of various antenna designs and optimization of system performance we plan to expand to 2048 antennas. We estimate that BURSTT-256 will detect and localize $\sim$100 bright ($\geq$100 Jy ms) FRBs per year. Another advantage of BURSTT's large FoV and continuous operation will be greatly enhanced monitoring of FRBs for repetition. The current lack of sensitive all-sky observations likely means that many repeating FRBs are currently cataloged as single-event FRBs., Published version
- Published
- 2022
29. TAROGE-M: radio antenna array on antarctic high mountain for detecting near-horizontal ultra-high energy air showers
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Shih-Hao Wang, Jiwoo Nam, Pisin Chen, Yaocheng Chen, Taejin Choi, Young-bae Ham, Shih-Ying Hsu, Jian-Jung Huang, Ming-Huey A. Huang, Geonhwa Jee, Jongil Jung, Jieun Kim, Chung-Yun Kuo, Hyuck-Jin Kwon, Changsup Lee, Chung-Hei Leung, Tsung-Che Liu, Yu-Shao J. Shiao, Bok-Kyun Shin, Min-Zu Wang, Yu-Hsin Wang, Astrid Anker, Steven W. Barwick, Dave Z. Besson, Sjoerd Bouma, Maddalena Cataldo, Geoffrey Gaswint, Christian Glaser, Steffen Hallmann, Jordan C. Hanson, Jakob Henrichs, Stuart A. Kleinfelder, Robert Lahmann, Zachary S. Meyers, Anna Nelles, Alexander Novikov, Manuel P. Paul, Lilly Pyras, Christopher Persichilli, Ilse Plaisier, Ryan Rice-Smith, Mohammad F.H. Seikh, Joulien Tatar, Christoph Welling, and Leshan Zhao
- Subjects
Astronomy and Astrophysics - Abstract
The TAROGE-M radio observatory is a self-triggered antenna array on top of the ∼2700 m high Mt. Melbourne in Antarctica, designed to detect impulsive geomagnetic emission from extensive air showers induced by ultra-high energy (UHE) particles beyond 1017 eV, including cosmic rays, Earth-skimming tau neutrinos, and particularly, the “ANITA anomalous events” (AAE) from near and below the horizon. The six AAE discovered by the ANITA experiment have signal features similar to tau neutrinos but that hypothesis is in tension either with the interaction length predicted by Standard Model or with the flux limits set by other experiments. Their origin remains uncertain, requiring more experimental inputs for clarification. The detection concept of TAROGE-M takes advantage of a high altitude with synoptic view toward the horizon as an efficient signal collector, and the radio quietness as well as strong and near vertical geomagnetic field in Antarctica, enhancing the relative radio signal strength. This approach has a low energy threshold, high duty cycle, and is easy to extend for quickly enlarging statistics. Here we report experimental results from the first TAROGE-M station deployed in January 2020, corresponding to approximately one month of livetime. The station consists of six receiving antennas operating at 180–450 MHz, and can reconstruct source directions of impulsive events with an angular resolution of ∼0.3°, calibrated in situ with a drone-borne pulser system. To demonstrate TAROGE-M's ability to detect UHE air showers, a search for cosmic ray signals in 25.3-days of data together with the detection simulation were conducted, resulting in seven identified candidates. The detected events have a mean reconstructed energy of 0.95-0.31 +0.46 EeV and zenith angles ranging from 25° to 82°, with both distributions agreeing with the simulations, indicating an energy threshold at about 0.3 EeV. The estimated cosmic ray flux at that energy is 1.2-0.9 +0.7 × 10-16 eV-1 km-2 yr-1 sr-1, also consistent with results of other experiments. The TAROGE-M sensitivity to AAEs is approximated by the tau neutrino exposure with simulations, which suggests comparable sensitivity as ANITA's at around 1 EeV energy with a few station-years of operation. These first results verified the station design and performance in a polar and high-altitude environment, and are promising for further discovery of tau neutrinos and AAEs after an extension in the near future.
- Published
- 2022
30. Towards Ultimate Understanding Of The Universe - Proceedings Of The First Lecospa Symposium
- Author
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Pisin Chen and Pisin Chen
- Published
- 2012
31. Detection of Low-Energy X-rays Using YSO Scintillation Crystal Arrays for GRB Experiments
- Author
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M. B. Kim, Chia-Ping Chen, S. Jeong, S. I. Svertilov, J. M. Rodrigo, Tsung-Che Liu, Vasily Petrov, Jik Lee, G. Gaikov, C. J. Eyles, M.-H. A. Huang, Yenyun Chang, Jiwoo Nam, Sheng-Hsiung Chang, Vitaly Bogomolov, Il Han Park, Carl Budtz-Jørgensen, Mikhail Panasyuk, Jian Jung Huang, Gihan Hong, Ji-Eun Kim, Søren Brandt, N. N. Vedenkin, I. V. Yashin, Victor Reglero, Chia Ray Chen, Jakub Ripa, A. J. Castro-Tirado, Ming Zu Wang, Pisin Chen, Chih-Yang Lin, P. Connell, H. Lim, National Research Foundation of Korea, Roscosmos, European Commission, Ministerio de Economía y Competitividad (España), and Ministerio de Ciencia e Innovación (España)
- Subjects
Physics ,Scintillation ,Photomultiplier ,business.industry ,Physics::Instrumentation and Detectors ,Astrophysics::High Energy Astrophysical Phenomena ,Detector ,Elementary particle physics ,General Physics and Astronomy ,chemistry.chemical_element ,gamma-ray burst ,YSO ,QC793-793.5 ,Yttrium ,Crystal ,UBAT ,Flash (photography) ,Optics ,chemistry ,Observatory ,UFFO ,Gamma-ray burst ,business - Abstract
Full list of authors: Kim, Minbin; Ripa, Jakub; Park, Il H.; Bogomolov, Vitaly; Brandt, Søren; Budtz-Jørgensen, Carl; Castro-Tirado, Alberto J.; Chang, Sheng-Hsiung; Chang, Yenyun; Chen, Chia Ray; Chen, C. -W.; Chen, Pisin; Connell, Paul; Eyles, Chris; Gaikov, Georgii; Hong, Gihan; Huang, Jian Jung; Huang, Ming-Huey Alfred; Jeong, Soomin; Kim, Jieun; Lee, Jik; Lim, Heuijin; Lin, Chih-Yang; Liu, Tsung-Che; Nam, Jiwoo; Panasyuk, Mikhail; Petrov, Vasily; Reglero, Victor; Rodrigo, Juana M.; Svertilov, Sergey; Vedenkin, Nikolay; Wang, Ming Zu; Yashin, Ivan.--This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited., We developed an X-ray detector using 36 arrays, each consisting of a 64-pixellated yttrium oxyorthosilicate (YSO) scintillation crystal and a 64-channel multi-anode photomultiplier tube. The Xray detector was designed to detect X-rays with energies lower than 10 keV, primarily with the aim of localizing gamma-ray bursts (GRBs). YSO crystals have no intrinsic background, which is advantageous for increasing low-energy sensitivity. The fabricated detector was integrated into UBAT, the payload of the Ultra-Fast Flash Observatory (UFFO)/Lomonosov for GRB observation. The UFFO was successfully operated in space in a low-Earth orbit. In this paper, we present the responses of the X-ray detector of the UBAT engineering model identical to the flight model, using241 Am and55 Fe radioactive sources and an Amptek X-ray tube. We found that the X-ray detector can measure energies lower than 5 keV. As such, we expect YSO crystals to be good candidates for the X-ray detector materials for future GRB missions. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland., This study was supported by grants from the Korean National Research Foundation (NRF-2017K1A4A3015188, NRF-2021R1A2B5B03002645, and NRF-2019H1D3A2A02060090). The Russian work was partially supported by ROSCOSMOS grants and by RFFI grant No. 13-02-12175 and No.15-35-21038 and support from the Development Program of Lomonosov Moscow State University is acknowledged. AJCT acknowledges support from the Spanish MINECO Projects AYA 2009-14000-C03-01/ESP and AYA2015-1718-R (including EU/FEDER funds). The authors thank Taiwan’s National Science Council Vanguard Program (100-2119-M-002-025) and Ministry of Science and Technology (MOST) for the funding (104-2811-M-002-160). MBK acknowledges the support from NRF-2015-GPF., With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709.
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- 2021
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32. Development of drone-borne aerial calibration pulser system for radio observatories of ultra-high energy air showers
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B. K. Shin, Tsung-Che Liu, Christian Hornhuber, David Zeke Besson, Min-Zu Wang, Jiwoo Nam, Jian-Jung Huang, M.-H. A. Huang, Shih-Ying Hsu, Pisin Chen, Chung Hei Leung, Yaocheng Chen, Alexander Novikov, Yu-Hsin Wang, Chung-Yun Kuo, R. Young, and Shih-Hao Wang
- Subjects
Attenuator (electronics) ,Impulse generator ,Astrophysics::Instrumentation and Methods for Astrophysics ,Calibration ,Environmental science ,Cosmic ray ,Antenna (radio) ,Differential GPS ,Energy (signal processing) ,Drone ,Remote sensing - Abstract
We present a portable calibration pulser system applied to radio antennas in order to detect ultra-high energy cosmic rays and neutrinos. The system consists of a solid-state high-voltage impulse generator, a digital attenuator, a wide band (150-350 MHz) bi-cone antenna, and a differential GPS. Taking an advantage of light weight of each component (less than $1.4$ kg), we developed an airborne calibration system by attaching them on a commercial drone. This system will be used for TAROGE experiment in high mountains as well as in Antarctica. We will report on its design, construction, performance, and potential applications for future radio experiments.
- Published
- 2021
33. Development of an in-situ calibration device of firn properties for Askaryan neutrino detectors
- Author
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Manuel P. Paul, D. Z. Besson, Ilse Plaisier, Jiayi Liu, Shih-Hao Wang, Arianna, Stuart A. Kleinfelder, S. R. Klein, G. Gaswint, Steven W. Barwick, Robert Lahmann, Jiwoo Nam, Daniel García Fernández, Ryan Rice-Smith, Leshan Zhao, A. Anker, Mitchell Magnuson, C. Persichilli, Jordan C. Hanson, Lilly Pyras, Anna Nelles, Christoph Welling, Steffen Hallmann, N. Bingefors, Hans Bernhoff, Pierre Baldi, Alexander Novikov, Stephen McAleer, Maddalena Cataldo, Jakob Beise, Zach Meyers, Christian Glaser, Allan Hallgren, Pisin Chen, and J. Tatar
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Physics ,Neutrino detector ,Firn ,In situ calibration ,Remote sensing - Published
- 2021
34. TAROGE-M: Radio Observatory on Antarctic High Mountain for Detecting Near-Horizon Ultra-High Energy Air Showers
- Author
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Ilse Plaisier, N. Bingefors, Daniel García Fernández, J. Tatar, Chung-Yun Kuo, Stephen McAleer, Leshan Zhao, Mitchell Magnuson, Allan Hallgren, Pisin Chen, Jordan C. Hanson, D. Z. Besson, Christoph Welling, Steven W. Barwick, A. Nelles, M.-H. A. Huang, Yu-Shao Jerry Shiao, Tsung-Che Liu, Pierre Baldi, Min-Zu Wang, Ryan Rice-Smith, Yaocheng Chen, A. Anker, C. Persichilli, G. Gaswint, Jiayi Liu, Manuel P. Paul, Robert Lahmann, Chung-Hei Leung, Hans Bernhoff, Stuart A. Kleinfelder, Christian Glaser, Jakob Beise, S. R. Klein, Yu-Hsin Wang, Jiwoo Nam, Jian-Jung Huang, Alexander Novikov, and Shih-Hao Wang
- Subjects
Astrophysics::High Energy Astrophysical Phenomena ,Transmitter ,Astrophysics::Instrumentation and Methods for Astrophysics ,Cosmic ray ,law.invention ,Antenna array ,Earth's magnetic field ,Observatory ,law ,Communications satellite ,Dipole antenna ,Geology ,Event reconstruction ,Remote sensing - Abstract
The TAROGE-M observatory is an autonomous antenna array on the top of Mt.~Melbourne ($\sim2700$ m altitude) in Antarctica, designed to detect radio pulses from ultra-high energy (over $10^{17}$ eV) air showers coming from near-horizon directions. The targeted sources include cosmic rays, Earth-skimming tau neutrinos, and most of all, the anomalous near-horizon upward-going events of yet unknown origin discovered by ANITA experiments. The detection concept follows that of ANITA: monitoring large area of ice from high-altitude and taking advantage of strong geomagnetic field and quiet radio background in Antarctica, whereas having significantly greater livetime and scalability. The TAROGE-M station, upgraded from its prototype built in 2019, was deployed in January 2020, and consists of 6 log-periodic dipole antennas pointing horizontally with bandwidth of 180-450 MHz. The station is then calibrated with drone-borne transmitter, with which the event reconstruction obtained $\sim0.3^\circ$ angular resolution. The station was then smoothly operating in the following month, with the live time of $\sim30$ days, before interrupted by a power problem, and its online filtering has identified several candidate cosmic-ray events and sent out via satellite communication. In this paper, the instrumentation of the station for polar and high-altitude environment, its radio-locating performance, the preliminary result on cosmic-ray detection, and the future extension plan are presented.
- Published
- 2021
35. Science case and detector concept for ARIANNA high energy neutrino telescope at Moore's Bay, Antarctica
- Author
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Zach Meyers, Arianna, Christian Glaser, Maddalena Cataldo, Steffen Hallmann, J. Tatar, A. Nelles, Hans Bernhoff, Allan Hallgren, Jiayi Liu, Alexander Novikov, Stuart A. Kleinfelder, Pisin Chen, Jakob Beise, D. Z. Besson, Lilly Pyras, Leshan Zhao, Ilse Plaisier, Ryan Rice-Smith, Shih-Hao Wang, Daniel García Fernández, Mitchell Magnuson, Jordan C. Hanson, N. Bingefors, S. W. Barwick, Manuel P. Paul, Jiwoo Nam, Pierre Baldi, Steven W. Barwick, Stephen McAleer, G. Gaswint, Christoph Welling, A. Anker, C. Persichilli, Robert Lahmann, and S. R. Klein
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Physics ,High energy ,Detector ,Neutrino telescope ,Astronomy ,Bay - Published
- 2021
36. A novel trigger based on neural networks for radio neutrino detectors
- Author
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N. Bingefors, Hans Bernhoff, Steven W. Barwick, Stephen McAleer, Shih-Hao Wang, Zach Meyers, Jakob Beise, Stuart A. Kleinfelder, Christian Glaser, Jiwoo Nam, Ryan Rice-Smith, G. Gaswint, Arianna, Alexander Novikov, Lilly Pyras, Anna Nelles, D. Z. Besson, Pierre Baldi, Ilse Plaisier, Maddalena Cataldo, A. Anker, C. Persichilli, Robert Lahmann, Christoph Welling, Leshan Zhao, Mitchell Magnuson, Jordan C. Hanson, Steffen Hallmann, J. Tatar, Allan Hallgren, Pisin Chen, S. R. Klein, Daniel García Fernández, Manuel P. Paul, and Jiayi Liu
- Subjects
Physics ,Artificial neural network ,Neutrino detector ,Electronic engineering - Published
- 2021
37. Capabilities of ARIANNA: Neutrino Pointing Resolution and Implications for Future Ultra-high Energy Neutrino Astronomy
- Author
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Ilse Plaisier, Allan Hallgren, Pisin Chen, G. Gaswint, Hans Bernhoff, Jakob Beise, Jiayi Liu, J. Tatar, Alexander Novikov, Jiwoo Nam, Stuart A. Kleinfelder, Ryan Rice-Smith, A. Nelles, Daniel García Fernández, Leshan Zhao, A. Anker, C. Persichilli, D. Z. Besson, Mitchell Magnuson, Jordan C. Hanson, Zach Meyers, Shih-Hao Wang, Christian Glaser, S. W. Barwick, Pierre Baldi, Stephen McAleer, Maddalena Cataldo, Christoph Welling, S. R. Klein, Robert Lahmann, Manuel P. Paul, Arianna, Lilly Pyras, N. Bingefors, Steffen Hallmann, and Steven W. Barwick
- Subjects
Physics ,Optics ,Anechoic chamber ,business.industry ,Distortion ,Detector ,Angular resolution ,Neutrino astronomy ,Neutrino ,business ,Viewing angle ,Polarization (waves) - Abstract
A radio-frequency polarization measurement by the ARIANNA surface station was performed using a residual hole from the South Pole Ice Core (SPICEcore) Project. Radio pulses were emitted from a transmitter located down to 1.7 km below the snow surface. After deconvolving the raw signals for the detector response and attenuation from propagation through the ice, the signal pulses show no significant distortion and agree with a reference measurement of the emitter made in an anechoic chamber. The direction to transmitted radio pulse was measured with an angular resolution of 0.37 degree [statistical error]. For polarization, the statistical error of the polarization vector is depth dependent and below 1 degree. In addition, a slow systematic error as a function of depth is 2.7 degrees. Neither the direction or polarization measurement show a significant offset as a function of depth relative to expectation. We also report on the results of a simulation study of the ARIANNA neutrino direction and energy resolution. The software tool NuRadioMC was used to reconstruct the polarization and viewing angle to determine the neutrino direction. Multiple models of Askaryan radiation and detector sites along with a range of neutrino energies were evaluated. The neutrino space angle resolution was determined to be below 3 degrees, which is comparable to the systematic polarization uncertainty. Therefore it is expected that the polarization resolution, which is the dominant contribution to the neutrino space angle resolution, will be improved in future studies by determining and eliminating systematic effects.
- Published
- 2021
38. Hawking radiation as instantons
- Author
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Misao Sasaki, Pisin Chen, and Dong-han Yeom
- Subjects
Physics ,High Energy Physics - Theory ,Instanton ,Physics and Astronomy (miscellaneous) ,Black hole information paradox ,FOS: Physical sciences ,lcsh:Astrophysics ,General Relativity and Quantum Cosmology (gr-qc) ,General Relativity and Quantum Cosmology ,Gravitation ,Black hole ,Theoretical physics ,symbols.namesake ,High Energy Physics::Theory ,Hawking ,High Energy Physics - Theory (hep-th) ,lcsh:QB460-466 ,symbols ,lcsh:QC770-798 ,lcsh:Nuclear and particle physics. Atomic energy. Radioactivity ,Einstein ,Engineering (miscellaneous) ,Scalar field ,Hawking radiation - Abstract
There have been various interpretations of Hawking radiation proposed based on the perturbative approach, and all have confirmed Hawking's original finding. One major conceptual challenge of Hawking evaporation is the associated black hole information loss paradox, which remains unresolved. A key factor to the issue is the end-stage of the black hole evaporation. Unfortunately by then the evaporation process becomes non-perturbative. Aspired to provide a tool for the eventual solution to this problem, here we introduce a new interpretation of Hawking radiation as the tunneling of instantons. We study instantons of a massless scalar field in Einstein gravity. We consider a complex-valued instanton that connects an initial pure black hole state to a black hole with a scalar field that represents the Hawking radiation at future null infinity, where its action depends only on the areal entropy difference. By comparing it with several independent approaches to Hawking radiation in the perturbative limit, we conclude that Hawking radiation may indeed be described by a family of instantons. Since the instanton approach can describe non-perturbative processes, we hope that our new interpretation and holistic method may shed lights on the information loss problem., 17 pages, 7 figures
- Published
- 2019
39. Quantum Power Distribution of Relativistic Acceleration Radiation: Classical Electrodynamic Analogies with Perfectly Reflecting Moving Mirrors
- Author
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Maksat Temirkhan, Michael R. R. Good, Pisin Chen, and Abay Zhakenuly
- Subjects
High Energy Physics - Theory ,Physics and Astronomy (miscellaneous) ,Distribution (number theory) ,Point particle ,General Mathematics ,FOS: Physical sciences ,General Relativity and Quantum Cosmology (gr-qc) ,Radiation ,Lorentz covariance ,quantum power distribution ,01 natural sciences ,General Relativity and Quantum Cosmology ,3 + 1-dimensions ,Acceleration ,0103 physical sciences ,Computer Science (miscellaneous) ,Classical electromagnetism ,010306 general physics ,Quantum ,Physics ,Quantum Physics ,010308 nuclear & particles physics ,lcsh:Mathematics ,moving mirrors ,lcsh:QA1-939 ,Physics::Classical Physics ,Power (physics) ,High Energy Physics - Theory (hep-th) ,Chemistry (miscellaneous) ,Quantum electrodynamics ,Quantum Physics (quant-ph) - Abstract
We find the quantum power emitted and distribution in $3+1$-dimensions of relativistic acceleration radiation using a single perfectly reflecting mirror via Lorentz invariance demonstrating close analogies to point charge radiation in classical electrodynamics., 6 pages, 2 figures, Appendix
- Published
- 2021
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40. Quantum Aspects Of Beam Physics 2003 - Proceedings Of The Joint 28th Icfa Advanced Beam Dynamics & Advanced & Novel Accelerators Workshop
- Author
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Pisin Chen, Kevin Reil and Pisin Chen, Kevin Reil
- Published
- 2004
41. Quantum Aspects Of Beam Physics, 18th Advanced Icfa Beam Dynamics Workshop
- Author
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Pisin Chen and Pisin Chen
- Published
- 2002
42. Particle production by a relativistic semitransparent mirror in (1+3)D Minkowski spacetime
- Author
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Kuan-Nan Lin, Pisin Chen, and Chih-En Chou
- Subjects
Massless particle ,Physics ,Formalism (philosophy of mathematics) ,Spacetime ,010308 nuclear & particles physics ,0103 physical sciences ,Minkowski space ,Gravitational collapse ,Plane mirror ,010306 general physics ,01 natural sciences ,Mathematical physics - Abstract
Production of massless, scalar particles by a relativistic, semitransparent, plane mirror in $(1+3)\mathrm{D}$ Minkowski spacetime based on the Barton-Calogeracos (BC) action is investigated. The corresponding Bogoliubov coefficients are derived for a mirror with arbitrary, relativistic trajectories. We apply our derived formula to two specific trajectories. One is commonly used in the $(1+1)\mathrm{D}$ literature to mimic gravitational collapse theoretically, and the other is proposed to be realizable experimentally. In addition, we identify the relation between the particle spectrum and the particle production probability, and we demonstrate the equivalence between our approach and the existing approach in the literature, which is restricted to $(1+1)\mathrm{D}$. In short, our treatment extends the study to $(1+3)\mathrm{D}$ spacetime for a relativistic, plane mirror. Lastly, we offer a third approach for finding the particle spectrum using the S-matrix formalism.
- Published
- 2021
43. Lessons from black hole quasinormal modes in modified gravity
- Author
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Pisin Chen, Che-Yu Chen, and Mariam Bouhmadi-López
- Subjects
High Energy Physics - Theory ,Photon ,Geodesic ,General relativity ,Astrophysics::High Energy Astrophysical Phenomena ,General Physics and Astronomy ,FOS: Physical sciences ,General Relativity and Quantum Cosmology (gr-qc) ,01 natural sciences ,General Relativity and Quantum Cosmology ,Gravitation ,symbols.namesake ,Theoretical physics ,Binary black hole ,0103 physical sciences ,Einstein ,010306 general physics ,Physics ,010308 nuclear & particles physics ,Gravitational wave ,Astrophysics - Astrophysics of Galaxies ,Black hole ,High Energy Physics - Theory (hep-th) ,Astrophysics of Galaxies (astro-ph.GA) ,symbols - Abstract
Quasinormal modes of perturbed black holes have recently gained much interest because of their tight relations with the gravitational wave signals emitted during the post-merger phase of a binary black hole coalescence. One of the intriguing features of these modes is that they respect the no-hair theorem, and hence, they can be used to test black hole space-times and the underlying gravitational theory. In this paper, we exhibit three different aspects of how black hole quasinormal modes could be altered in theories beyond Einstein general relativity. These aspects are the direct alterations of quasinormal modes spectra as compared with those in general relativity, the violation of the geometric correspondence between the high-frequency quasinormal modes and the photon geodesics around the black hole, and the breaking of the isospectrality between the axial and polar gravitational perturbations. Several examples will be provided in each individual case. The prospects and possible challenges associated with future observations will be also discussed., Comment: 12 pages, 8 figures
- Published
- 2021
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44. Modification to the Hawking temperature of a dynamical black hole by a flow-induced supertranslation
- Author
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Yu-Hsien Kung, Pisin Chen, and Hsu-Wen Chiang
- Subjects
High Energy Physics - Theory ,Nuclear and High Energy Physics ,Black Holes ,General relativity ,Black hole information paradox ,FOS: Physical sciences ,General Relativity and Quantum Cosmology (gr-qc) ,01 natural sciences ,General Relativity and Quantum Cosmology ,0103 physical sciences ,lcsh:Nuclear and particle physics. Atomic energy. Radioactivity ,010306 general physics ,Physics ,010308 nuclear & particles physics ,Horizon ,Space-Time Symmetries ,Charge (physics) ,Black hole ,Classical mechanics ,Unruh effect ,High Energy Physics - Theory (hep-th) ,lcsh:QC770-798 ,Diffeomorphism ,Classical Theories of Gravity ,Hawking radiation - Abstract
One interesting proposal to solve the black hole information loss paradox without modifying either general relativity or quantum field theory, is the soft hair, a diffeomorphism charge that records the anisotropic radiation in the asymptotic region. This proposal, however, has been challenged, given that away from the source the soft hair behaves as a coordinate transformation that forms an Abelian group, thus unable to store any information. To maintain the spirit of the soft hair but circumvent these obstacles, we consider Hawking radiation as a probe sensitive to the entire history of the black hole evaporation, where the soft hairs on the horizon are induced by the absorption of a null anisotropic flow, generalizing the shock wave considered in [1, 2]. To do so we introduce two different time-dependent extensions of the diffeomorphism associated with the soft hair, where one is the backreaction of the anisotropic null flow, and the other is a coordinate transformation that produces the Unruh effect and a Doppler shift to the Hawking spectrum. Together, they form an exact BMS charge generator on the entire manifold that allows the nonperturbative analysis of the black hole horizon, whose surface gravity, i.e. the Hawking temperature, is found to be modified. The modification depends on an exponential average of the anisotropy of the null flow with a decay rate of 4M, suggesting the emergence of a new 2-D degree of freedom on the horizon, which could be a way out of the information loss paradox.
- Published
- 2020
45. Reflectivity and Spectrum of Relativistic Flying Plasma Mirrors
- Author
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Yuan Fang, Pisin Chen, and Yung-Kun Liu
- Subjects
Physics ,Photon ,business.industry ,Extreme ultraviolet lithography ,Black hole information paradox ,FOS: Physical sciences ,Plasma ,Condensed Matter Physics ,Laser ,Physics - Plasma Physics ,law.invention ,Plasma Physics (physics.plasm-ph) ,Black hole ,Acceleration ,Optics ,Relativistic plasma ,law ,business - Abstract
Flying plasma mirrors induced by intense lasers has been proposed as a promising way to generate few-cycle EUV or X-ray lasers. In addition, if such a relativistic plasma mirror can accelerate, then it would serve as an analog black hole to investigate the information loss paradox associated with the black hole Hawking evaporation. Among these applications, the reflectivity, which is usually frequency-dependent, would affect the outgoing photon spectrum and therefore impact on the analysis of the physics under investigation. In this paper, these two issues are investigated analytically and numerically with one-dimensional particle-in-cell (PIC) simulations. Based on our simulation results, we propose a new model that provides a better estimate of the reflectivity than those studied previously. Besides, we found that the peak frequency of the reflected spectrum of a gaussian incident wave deviates from the expected value, $4\gamma^2\omega$, due to the dependence of reflectivity on the frequency of the incident wave., Comment: 7 pages, 5 figures
- Published
- 2020
46. THE SLEWING MIRROR TELESCOPE AND THE DATA-ACQUISITION SYSTEM
- Author
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V. Reglero, G. W. Na, A. J. Castro-Tirado, Yong-Jin Choi, S. Dagoret-Campagne, S. I. Svertilov, J. M. Rodrigo, S. Ahmad, Meng Wang, J. Lee, H. Lim, Tsung-Che Liu, Il Han Park, S. Jeong, Niels Lund, J. E. Kim, Eric V. Linder, Jiwoo Nam, P. Barrillon, Jakub Ripa, A. Jung, M. I. Panasyuk, S. W. Kim, P. H. Connell, K. W. Min, M. B. Kim, Carl Budtz-Jørgensen, Pisin Chen, C. J. Eyles, J. E. Suh, I. V. Yashin, Søren Brandt, N. N. Vedenkin, M.-H. A. Huang, Y. W. Kim, B. Grossan, George F. Smoot, and A.S. Krasnov
- Subjects
Telescope ,Data acquisition ,Optics ,law ,business.industry ,Computer science ,business ,law.invention - Published
- 2020
47. High-elevation synoptic radio array for detection of upward moving air-showers, deployed in the Antarctic mountains
- Author
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Tsung-Che Liu, S.-H. Wang, Taroge, Pisin Chen, J.-J. Huang, Y.-S. Shiao, C. Hornhuber, Alexander Novikov, M.-H. A. Huang, S.-Y. Hsu, Min-Zu Wang, Jiwoo Nam, Y.-H. Wang, Y.C. Chen, C.-Y. Kuo, B. K. Shin, D. J. Besson, and C.H. Leung
- Subjects
High elevation ,Detector ,Elevation ,Sensitivity (electronics) ,Geology ,Remote sensing - Abstract
We present a new radio array experiment on the top of the highest mountains in Antarctica, to detect upward moving air-showers similar to those recently reported by the ANITA experiment. The detection concept follows ANITA, but has significantly greater livetime and extendibility. We propose to install 10 stations over the next 5 years to obtain sufficient sensitivity to test ANITA’s `mystery events'. As the first step, we installed a prototype station (TAROGE-M) consisting of 5 LPDA antennas, atop Mt. Melbourne, Antarctica at an elevation of 2730 m, in Feb-Mar 2019. We present the scientific potential, detector design and construction, as well as the initial performance of the prototype station.
- Published
- 2020
48. IceCube-Gen2: The Window to the Extreme Universe
- Author
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J. Kim, A. Gartner, A. Obertacke Pollmann, B. Hoffmann, J. L. Kelley, Markus Ahlers, Jenni Adams, Akimichi Taketa, D. van Eijk, Daniel Bindig, G. H. Collin, T. C. Arlen, Robert Lahmann, J. J. Beatty, Tianlu Yuan, U. Nauman, Azadeh Keivani, Y. L. Li, Karl J. Clark, T. Kintscher, M. Song, T. L. Carver, Paras Koundal, Michael Kovacevich, Christian Glaser, Frederik Hermann Lauber, T. Huege, Erik Ganster, Benedikt Riedel, D. Seckel, Anna Nelles, R. G. Stokstad, F. McNally, R. Maunu, M. Prado Rodriguez, Kayla Leonard, N. Kurahashi, James E. Braun, Amy Connolly, Samvel Ter-Antonyan, A. Terliuk, Justin Lanfranchi, Pranav Dave, Jannis Necker, C. Wendt, S. Wren, A. Sharma, Sukeerthi Dharani, David Vannerom, M. H. Shaevitz, Alexander Trettin, Reina H. Maruyama, Francis Halzen, J. Merz, K. Krings, Rasha Abbasi, Ben Smithers, Qinrui Liu, M. J. Larson, T. Anderson, Summer Blot, G. de Wasseige, I. Ansseau, D. Hebecker, Jorge Torres, Killian Holzapfel, Martina Karl, C. J. Lozano Mariscal, John Hardin, Jean Pierre Twagirayezu, Daniel García-Fernández, T. Stezelberger, S. Mandalia, E. O'Sullivan, R. Hoffmann, M. Plum, Juliana Stachurska, H. Dembinski, C. Pérez de los Heros, S. Márka, G. WSullivan, A. Haungs, Paul Coppin, Z. Griffith, J. C. Gallagher, Saskia Philippen, Federica Bradascio, Jochen M. Schneider, Srubabati Goswami, Andrea Turcati, Wing Yan Ma, Nahee Park, Y. Makino, Sarah Mancina, C. Walck, M. Kauer, Suyong Choi, Anna Franckowiak, Tobias Hoinka, Chad Finley, David Kappesser, T. Gregoire, Ella Roberts, J. van Santen, S. De Ridder, Jan Weldert, Chunfai Tung, F. Jonske, Ken'ichi Kin, L. Halve, Philipp Eller, K. Hultqvist, N. L. Strotjohann, H. Dujmovic, Vedant Basu, M. A. Unland Elorrieta, Alex Pizzuto, K. D. de Vries, I. CMariş, Gerrit Wrede, R. Gernhaeuser, Thomas Huber, Matti Jansson, Thomas K. Gaisser, M. Richman, Christoph Tönnis, James DeLaunay, Gary Binder, K.-H. Becker, Ek Narayan Paudel, Allan Hallgren, U. Latif, Hiroyuki Tanaka, I. Safa, Steve Sclafani, J. Kiryluk, K. Andeen, P. B. Price, H. Schieler, Kirill Filimonov, Segev BenZvi, Alexander Fritz, D. Z. Besson, Darren Grant, Marjon Moulai, Yiqian Xu, Felix Henningsen, S. Robertson, Aswathi Balagopal, Francesco Lucarelli, Pisin Chen, Matt Dunkman, Merlin Schaufel, Patrick Allison, Spencer Klein, Cosmin Deaconu, Tim Ruhe, A. Ludwig, George Japaridze, Javier Gonzalez, C. B. Krauss, Roxanne Turcotte, T. O. B. Schmidt, Simona Toscano, Roger Moore, P. Heix, R. S. Busse, Chujie Chen, Pablo Correa, L. Gerhard, S. De Kockere, J. Felde, Surujhdeo Seunarine, R. Snihur, J. Buscher, D. Rysewyk Cantu, A. Weindl, R. Hellauer, Giorgio Maggi, H. Niederhausen, Mauricio Bustamante, D. Southall, Julia Böttcher, J. Bourbeau, Lenka Tomankova, Maryon Ahrens, A. Burgman, Christopher Wiebusch, Darko Veberič, Juanan Aguilar, T. R. Wood, Christian Spiering, Frederik Tenholt, R. Nagai, L. Schumacher, C. De Clercq, Benjamin Hokanson-Fasig, L. V. Nguyen, C. Lagunas Gualda, K. Hughes, Kara Hoffman, C. Alispach, J. M. LoSecco, Joshua Hignight, K. Helbing, Timo Sturwald, Xinyue Kang, Richard Naab, Kunal Deoskar, Janet Conrad, Zackary Meyers, K. Meagher, Mehmet Gunduz, Agnieszka Leszczyńska, R. C. Bay, David A. Williams, Kurt Woschnagg, M. Zöcklein, M. Silva, Claudio Kopper, Eric Oberla, Ramesh Koirala, E. Cheung, Thomas Stuttard, Martin Rongen, Najia Moureen Binte Amin, R. Cross, Paul Evenson, A. Karle, Sebastian Böser, Seongjin In, Johannes Werthebach, J. P. Lazar, Markus Ackermann, Austin Schneider, Yang Lyu, Justin Vandenbroucke, Juan Carlos Diaz-Velez, Beverley A. Clark, Timo Karg, Sarah Pieper, Hershal Pandya, Wolfgang Rhode, Zhedong Zhang, P. Schlunder, A. Ishihara, Elisa Resconi, Subir Sarkar, William Luszczak, Clara E. Hill, Ava Ghadimi, Alessio Porcelli, Alan Coleman, J. Auffenberg, Grant Parker, Robert Stein, Dirk Ryckbosch, Benjamin Bastian, Anastasia Maria Barbano, Abhishek Desai, T. Kittler, J. Nam, P. Mallik, E. Blaufuss, S. Zierke, T. Stanev, M. Bohmer, Stephan Meighen-Berger, Simone Garrappa, P. Muth, Dmitry Chirkin, M. E. Huber, Marcos Santander, Christoph Raab, Nadège Iovine, J. Becker Tjus, L. Classen, Colin Turley, S. C. Nowicki, K. Farrag, M. Kleifges, O. Kalekin, A. Olivas, Alexander Kappes, D. Berley, G. C. Hill, Abigail G. Vieregg, Frank G. Schröder, D. Heinen, Erin Carnie-Bronca, N. Kulacz, D. Tosi, J. C. Hanson, Bunheng Ty, Ralph Engel, Moritz Kellermann, Gisela Anton, Elisa Lohfink, Elisa Bernardini, Damian Pieloth, Ali Kheirandish, Jan Soedingrekso, Giovanni Renzi, Michael DuVernois, Jannes Brostean-Kaiser, K. Wiebe, S. Fahey, A. R. Fazely, Tyce DeYoung, J. Lünemann, Thomas Ehrhardt, Nathan Whitehorn, Immacolata Carmen Rea, M. U. Nisa, Aaron Fienberg, Gerald Przybylski, G. Krückl, L. Papp, Amirreza Raissi, L. Köpke, Chris Weaver, R. Halliday, Alejandro Diaz, Stephanie Bron, S. Söldner-Rembold, James Pinfold, Ryan Burley, M. Riegel, H. Bagherpour, Stephanie Wissel, Olga Botner, Y. Pan, A. Steuer, S. Tilav, D. Kang, M. deWith, V. Baum, J. P. Yanez, I. Taboada, Stephen L. Hauser, Raamis Hussain, Michael O. Wolf, M. Stamatikos, John Evans, Shefali Shefali, Christoph Welling, Abdul Rehman, Carsten Rott, K. Tollefson, A. Goldschmidt, Y. Popovych, Troels Petersen, S. E. Sanchez Herrera, Simeon Reusch, S. Hickford, Xianwu Xu, J. Sandroos, C. Bohm, R. Joppe, Spencer Axani, Sebastian Baur, Carlos Arguelles, Jessie Micallef, Teppei Katori, K. Rawlins, James Madsen, Lu Lu, M. G. Aartsen, T. Glüsenkamp, M. Meier, Michael Campana, P. Sandstrom, Kendall Mahn, B. J. P. Jones, K. Hoshina, Glenn Spiczak, Andres Medina, G. Momenté, D. Mockler, M. Rameez, D. F. Cowen, Daria Pankova, E. Friedman, R. Morse, T. Montaruli, E. Unger, Maximilian Karl Scharf, P. Peiffer, J. Stettner, Gerrit Roellinghoff, Mirco Hunnefeld, Marie Oehler, Max Renschler, D. J. Koskinen, E. Bourbeau, Spencer Griswold, Maria Tselengidou, D. Soldin, Z. Márka, Minjin Jeong, L. Rauch, S. Yoshida, N. van Eijndhoven, C. Haack, Emily Dvorak, D. R. Nygren, Marek Kowalski, Kael Hanson, Paolo Desiati, J. Haugen, Lars Steffen Weinstock, Johan Wulff, Won Nam Kang, Timothyblake Watson, X. Bai, G. Neer, Konstancja Satalecka, Theo Glauch, U. Katz, Alexander Sandrock, Ilse Plaisier, K. Mase, D. B. Fox, Hermann Kolanoski, M. J. Weiss, Stef Verpoest, Imre Bartos, David J. Smith, S. Kopper, René Reimann, Leander Fischer, F. Huang, Matthias Vraeghe, Physics, Faculty of Sciences and Bioengineering Sciences, Vriendenkring VUB, and Elementary Particle Physics
- Subjects
Physics ,High Energy Astrophysical Phenomena (astro-ph.HE) ,astro-ph.HE ,Nuclear and High Energy Physics ,Active galactic nucleus ,010308 nuclear & particles physics ,High-energy astronomy ,Gravitational wave ,media_common.quotation_subject ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astronomy ,FOS: Physical sciences ,Cosmic ray ,01 natural sciences ,Universe ,Neutron star ,0103 physical sciences ,Neutrino ,Neutrino astronomy ,Astrophysics - High Energy Astrophysical Phenomena ,010303 astronomy & astrophysics ,media_common - Abstract
The observation of electromagnetic radiation from radio to $\gamma$-ray wavelengths has provided a wealth of information about the universe. However, at PeV (10$^{15}$ eV) energies and above, most of the universe is impenetrable to photons. New messengers, namely cosmic neutrinos, are needed to explore the most extreme environments of the universe where black holes, neutron stars, and stellar explosions transform gravitational energy into non-thermal cosmic rays. The discovery of cosmic neutrinos with IceCube has opened this new window on the universe. In this white paper, we present an overview of a next-generation instrument, IceCube-Gen2, which will sharpen our understanding of the processes and environments that govern the universe at the highest energies. IceCube-Gen2 is designed to: 1) Resolve the high-energy neutrino sky from TeV to EeV energies; 2) Investigate cosmic particle acceleration through multi-messenger observations; 3) Reveal the sources and propagation of the highest energy particles in the universe; 4) Probe fundamental physics with high-energy neutrinos. IceCube-Gen2 will increase the annual rate of observed cosmic neutrinos by a factor of ten compared to IceCube, and will be able to detect sources five times fainter than its predecessor. Furthermore, through the addition of a radio array, IceCube-Gen2 will extend the energy range by several orders of magnitude compared to IceCube. Construction will take 8 years and cost about \$350M. The goal is to have IceCube-Gen2 fully operational by 2033. IceCube-Gen2 will play an essential role in shaping the new era of multi-messenger astronomy, fundamentally advancing our knowledge of the high-energy universe. This challenging mission can be fully addressed only in concert with the new survey instruments across the electromagnetic spectrum and gravitational wave detectors which will be available in the coming years., Comment: 56 pages, 29 figures
- Published
- 2020
49. A path(-integral) toward non-perturbative effects in Hawking radiation
- Author
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Pisin Chen, Misao Sasaki, and Dong-han Yeom
- Subjects
Physics ,High Energy Physics - Theory ,010308 nuclear & particles physics ,Black hole information paradox ,Evaporation ,FOS: Physical sciences ,Astronomy and Astrophysics ,General Relativity and Quantum Cosmology (gr-qc) ,01 natural sciences ,General Relativity and Quantum Cosmology ,Black hole ,Hawking ,High Energy Physics - Theory (hep-th) ,Space and Planetary Science ,Quantum electrodynamics ,0103 physical sciences ,Path integral formulation ,Non-perturbative ,010306 general physics ,Mathematical Physics ,Hawking radiation - Abstract
Hawking's seminal discovery of black hole evaporation was based on the semi-classical, perturbative method. Whether black hole evaporation may result in the loss of information remains undetermined. The solution to this paradox would most likely rely on the knowledge of the end-life of the evaporation, which evidently must be in the non-perturbative regime. Here we reinterpret the Hawking radiation as the tunneling of instantons, which is inherently non-perturbative. For definitiveness, we invoke the picture of shell-anti-shell pair production and show that it is equivalent to that of instanton tunneling. We find that such a shell pair production picture can help to elucidate firewalls and ER=EPR conjectures that attempt to solve the information paradox, and may be able to address the end-life issue toward an ultimate resolution., 5 pages, 2 figures
- Published
- 2020
50. Eikonal black hole ringings in generalized energy-momentum squared gravity
- Author
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Pisin Chen and Che-Yu Chen
- Subjects
High Energy Physics - Theory ,Physics ,010308 nuclear & particles physics ,General relativity ,Eikonal equation ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,General Relativity and Quantum Cosmology (gr-qc) ,01 natural sciences ,General Relativity and Quantum Cosmology ,Action (physics) ,Eikonal approximation ,Black hole ,Gravitation ,symbols.namesake ,High Energy Physics - Theory (hep-th) ,Maxwell's equations ,0103 physical sciences ,Master equation ,symbols ,010306 general physics ,Mathematical physics - Abstract
In the scope of black hole spectroscopy, several attempts have been made in the past decades in order to test black holes or gravitational theories via black hole quasinormal modes. In the eikonal approximation, the quasinormal modes are generically associated with the photon ring of the black hole. This correspondence is valid for most cases in general relativity, but may not be true in other theories of gravity. In this paper, we consider the generalized energy-momentum squared gravity in which matter fields are non-minimally coupled to geometry. We investigate the axial perturbations of the charged black holes in this model, without assuming any explicit expression of the action functional. After obtaining the modified Klein-Gordon equation and the modified Maxwell equations, we perturb the gravitational equations and the modified Maxwell equations to derive the coupled master equations of the axial perturbations. In the presence of the non-minimal coupling between matter and geometry, the correspondence between the eikonal quasinormal modes and the photon ring is not satisfied in general. Also, the two coupled fields of the axial perturbations are found to propagate independently and they do not share the same quasinormal frequencies in the eikonal limit., 11 pages. Updated to match the published version
- Published
- 2020
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