Article
Astronomy & Astrophysics
Kabir Chakravarti, Rajes Ghosh, Sudipta Sarkar
Summary: This study investigates the effect of black hole area quantization on the formation of gravitational wave echoes and explores how the echo waveform may depend on various model parameters. It opens up a new avenue for future gravitational wave observations to distinguish different models of area quantization and provides a novel probe to study near-horizon physics.
Article
Physics, Particles & Fields
I. D. D. Carvalho, J. Furtado, R. R. Landim, G. Alencar
Summary: In this paper, the authors investigate the effects of scalar and vector unparticle corrections on cosmic and black strings. They first analyze the static cosmic string ansatz and obtain the solution in terms of Bessel functions. The solution for a black string in the unparticle scenario is also derived. The study reveals the presence of two regimes: a gravity-dominated regime and an ungravity dominated regime. Fractalization of the event horizon is found, indicating that unparticles naturally lead to fractal behavior. The thermodynamics of the black string in the ungravity scenario is studied, and phase transitions are found depending on the parameter d(U).
EUROPEAN PHYSICAL JOURNAL C
(2023)
Article
Physics, Particles & Fields
Mohsen Fathi, Samuel Lepe, J. R. Villanueva
Summary: This paper analyzes interesting features of the thermodynamics of the rotating BTZ black hole from the Caratheodory axiomatic postulate, explores adiabatic transformations, and discusses the implications for the second and third laws of black hole thermodynamics, specifically studying the merging of two extremal black holes in detail.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Astronomy & Astrophysics
Gaston Giribet, Juan Laurnagaray, Pedro Schmied
Summary: In many cases, the near-horizon geometry can be used to compute conserved charges and thermodynamic quantities of gravitational solutions. These charges are Noether charges associated with asymptotic isometries that preserve appropriate boundary conditions at the future horizon. This paper demonstrates the application of such computations in higher-dimensional solutions with event horizons of nontrivial topology, using the 5-dimensional black ring as a particular focus.
Article
Astronomy & Astrophysics
Davide Gerosa, Cecilia Maria Fabbri, Ulrich Sperhake
Summary: The study computes the irreducible mass of stellar-mass BHs observed by gravitational-wave interferometers and ranks black hole mergers according to their irreversibility, providing guidance for targeted tests of general relativity.
CLASSICAL AND QUANTUM GRAVITY
(2022)
Article
Physics, Multidisciplinary
Andrea Boido, Jerome P. Gauntlett, Dario Martelli, James Sparks
Summary: This article introduces an entropy function for supersymmetric accelerating black holes in four-dimensional anti-de Sitter space that can lift general Sasaki-Einstein manifolds X-7 to M-theory solutions. This allows for the computation of black hole entropy without knowing the explicit solutions. A dual holographic microstate counting can be obtained by computing certain supersymmetric partition functions of Chern-Simons-matter theories compactified on a spindle. A general prediction for a class of such partition functions in terms of blocks, each constructed from the partition function on a three-sphere, is made.
PHYSICAL REVIEW LETTERS
(2023)
Article
Astronomy & Astrophysics
F. C. Sobrinho, H. A. Borges, I. P. R. Baranov, S. Carneiro
Summary: Effective models of quantum black holes inspired by LQG successfully replace the classical singularity with a hypersurface of transition and have been able to describe Schwarzschild black holes as well as Planck scale black holes. The quantization method used by Alonso-Bardaji, Brizuela, and Vera preserves the classical form of the angular part of the metric and retains the same horizon area as in the classical theory. The exterior metric generated through a phase rotation shows that the Kretschmann scalar is the same as in the classical Schwarzschild solution, but with a screened central mass due to quantum fluctuations.
CLASSICAL AND QUANTUM GRAVITY
(2023)
Article
Astronomy & Astrophysics
Mariano Cadoni, Mauro Oi, Andrea P. Sanna
Summary: By describing the black hole as a statistical ensemble of quantum harmonic oscillators and working in the canonical ensemble, it is shown that in the large-mass black hole limit, the leading contribution to the entropy is the Bekenstein-Hawking term, with a subleading contribution being a logarithmic correction. The number of oscillators is found to scale holographically with the area of the event horizon.
Article
Astronomy & Astrophysics
Gopal Yadav, Nitin Joshi
Summary: In this study, the researchers analyzed the information paradox and its resolution in Schwarzschild de-Sitter black hole spacetime using the island proposal. They found that the black hole island is located inside the black hole event horizon, contrary to the universal result for eternal black holes, and the cosmological island is also located inside the cosmological event horizon. Moreover, they studied the effect of temperature on Page curves and observed that low-temperature black hole/de-Sitter patch exhibits Page curves at later times, while high-temperature black hole/de-Sitter patch shows the opposite behavior.
Article
Astronomy & Astrophysics
Soumen Roy, Anand S. Sengupta, K. G. Arun
Summary: The higher multipoles of gravitational wave signals are crucial for accurate reconstruction of source properties. This paper introduces a new method of detecting these signals by combining multiple events observed in interferometric gravitational wave detectors. Monte Carlo simulations suggest that a combination of about 100 events can lead to a detection probability of higher-multipole components exceeding 95%.
Article
Physics, Multidisciplinary
Arjun Bagchi, Daniel Grumiller, Mohammad Mehdi Sheikh-Jabbari
Summary: This paper proposes that 3D black holes are an ensemble of tensionless null string states. By evaluating the partition function and showing that their combinatorics reproduce the Bekenstein-Hawking entropy and its semiclassical logarithmic corrections.
Article
Astronomy & Astrophysics
Nicolo Burzilla, Breno L. Giacchini, Tiberio de Paula Netto, Leonardo Modesto
Summary: In this paper, we analyze the static spherically symmetric solutions of a sixth-derivative Lee-Wick gravity model and find interesting structures in the full parameter space, including horizon structures, mass gaps, and multiple regimes for black hole sizes. The thermodynamics of these solutions exhibit multiple mass scales for the remnants of the evaporation process and the possibility of cold black holes and quasi-stable intermediate configurations.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Physics, Particles & Fields
Ida M. Rasulian
Summary: This study proposes an effective model for an exponentially expanding universe in the brane-world scenario. The model consists of a 5D black hole and a brane close to the black hole horizon. The study reveals that the brane can acquire a de Sitter metric with a specific configuration and that the fluid density inside the brane contributes to the energy density, potentially as dark matter. Furthermore, it is observed that the presence of matter stabilizes the brane, with a de Sitter length qualitatively similar to the Schwarzschild radius of the universe due to matter.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Astronomy & Astrophysics
Rogerio Teixeira Cavalcanti, Julio Marny Hoff da Silva
Summary: The study presents the gravitational decoupling method and the resulting hairy black hole, and investigates the formation of quantum hairy black holes using the horizon quantum mechanics formalism. It allows us to determine the influence of external fields, characterized by hairy parameters, on the probability of spherically symmetric black hole formation and the generalized uncertainty principle.
Article
Physics, Particles & Fields
Cao H. Nam
Summary: In this study, the island rule is applied to compute the entanglement entropy of Hawking radiation and investigate the Page curve for eternal black holes in massive gravity. Results show that neutral and non-extremal charged black holes do not form islands early in evaporation, leading to a linear increase in entanglement entropy. On the other hand, extremal charged black holes face issues with divergence in metric at the curvature singularity without islands. The emergence of one island near the event horizon at late times leads to saturation of the entanglement entropy by the Bekenstein-Hawking entropy. Additionally, the impact of massive gravity parameters on various aspects is analyzed in detail.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Astronomy & Astrophysics
Saurya Das, Mitja Fridman, Gaetano Lambiase, Elias C. Vagenas
Summary: The paper discusses the unexplained baryon asymmetry in the Universe and proposes a new explanation framework that satisfies the Sakharov conditions and introduces the Generalized Uncertainty Principle and holographic principle to address this issue.
Article
Astronomy & Astrophysics
Mousumi Maitra, Debaprasad Maity, Bibhas Ranjan Majhi
Summary: The study investigates the Goldstone modes of Schwarzschild and Kerr black holes, finding that the effective semi-classical temperature of the Goldstone modes is proportional to the Hawking temperature, suggesting a potentially important role in understanding the microscopic description of horizon thermalization.
Review
Physics, Nuclear
A. Addazi, J. Alvarez-Muniz, R. Alves Batista, G. Amelino-Camelia, V Antonelli, M. Arzano, M. Asorey, J-L Atteia, S. Bahamonde, F. Bajardi, A. Ballesteros, B. Baret, D. M. Barreiros, S. Basilakos, D. Benisty, O. Birnholtz, J. J. Blanco-Pillado, D. Blas, J. Bolmont, D. Boncioli, P. Bosso, G. Calcagni, S. Capozziello, J. M. Carmona, S. Cerci, M. Chernyakova, S. Clesse, J. A. B. Coelho, S. M. Colak, J. L. Cortes, S. Das, V D'Esposito, M. Demirci, M. G. Di Luca, A. di Matteo, D. Dimitrijevic, G. Djordjevic, D. Dominis Prester, A. Eichhorn, J. Ellis, C. Escamilla-Rivera, G. Fabiano, S. A. Franchino-Vinas, A. M. Frassino, D. Frattulillo, S. Funk, A. Fuster, J. Gamboa, A. Gent, L. A. Gergely, M. Giammarchi, K. Giesel, J-F Glicenstein, J. Gracia-Bondia, R. Gracia-Ruiz, G. Gubitosi, E. Guendelman, I Gutierrez-Sagredo, L. Haegel, S. Heefer, A. Held, F. J. Herranz, T. Hinderer, J. I. Illana, A. Ioannisian, P. Jetzer, F. R. Joaquim, K-H Kampert, A. Karasu Uysal, T. Katori, N. Kazarian, D. Kerszberg, J. Kowalski-Glikman, S. Kuroyanagi, C. Lammerzahl, J. Levi Said, S. Liberati, E. Lim, I. P. Lobo, M. Lopez-Moya, G. G. Luciano, M. Manganaro, A. Marciano, P. Martin-Moruno, Manel Martinez, Mario Martinez, H. Martinez-Huerta, P. Martinez-Mirave, M. Masip, D. Mattingly, N. Mavromatos, A. Mazumdar, F. Mendez, F. Mercati, S. Micanovic, J. Mielczarek, A. L. Miller, M. Milosevic, D. Minic, L. Miramonti, V. A. Mitsou, P. Moniz, S. Mukherjee, G. Nardini, S. Navas, M. Niechciol, A. B. Nielsen, N. A. Obers, F. Oikonomou, D. Oriti, C. F. Paganini, S. Palomares-Ruiz, R. Pasechnik, V Pasic, C. Perez de los Heros, C. Pfeifer, M. Pieroni, T. Piran, A. Platania, S. Rastgoo, J. J. Relancio, M. A. Reyes, A. Ricciardone, M. Risse, M. D. Rodriguez Frias, G. Rosati, D. Rubiera-Garcia, H. Sahlmann, M. Sakellariadou, F. Salamida, E. N. Saridakis, P. Satunin, M. Schiffer, F. Schussler, G. Sigl, J. Sitarek, J. Sola Peracaula, C. F. Sopuerta, T. P. Sotiriou, M. Spurio, D. Staicova, N. Stergioulas, S. Stoica, J. Striskovic, T. Stuttard, D. Sunar Cerci, Y. Tavakoli, C. A. Ternes, T. Terzic, T. Thiemann, P. Tinyakov, M. D. C. Torri, M. Tortola, C. Trimarelli, T. Trzesniewski, A. Tureanu, F. R. Urban, E. C. Vagenas, D. Vernieri, V. Vitagliano, J-C Wallet, J. D. Zornoza
Summary: The exploration of the universe has entered a new era with the multi-messenger paradigm, providing us with more information about the universe and opening up the possibility of searching for quantum gravity phenomena.
PROGRESS IN PARTICLE AND NUCLEAR PHYSICS
(2022)
Article
Astronomy & Astrophysics
Avijit Bera, Surojit Dalui, Subir Ghosh, Elias C. Vagenas
Summary: This paper investigates the effects of quantum corrections on chaotic behavior in the dynamics of a (massless) probe particle near the horizon of a generalized Schwarzschild black hole. The study considers two possible origins for the modification of the black hole metric and shows that in both cases, the metric extensions lead to chaotic behavior, with chaos reached at relatively lower particle energy levels.
Article
Astronomy & Astrophysics
Surojit Dalui, Bibhas Ranjan Majhi
Summary: This study tests our previously proposed conjecture that the local instability created by the horizon serves as the source of the quantum temperature of a black hole. It has been demonstrated that this conjecture holds true for the more realistic case of Kerr black hole, in addition to the previously studied spherically symmetric static black hole.
Article
Physics, Particles & Fields
Pratyusha Chowdhury, Bibhas Ranjan Majhi
Summary: This study investigates the fate of initial entanglement between two accelerated detectors with respect to an observer attached to one of the detectors. The investigation considers both (1 + 1) and (1 + 3) spacetime dimensions, with the detectors interacting with real massless scalar fields through monopole terms. The study is conducted for both non-thermal and thermal fields, and shows that increasing the field temperature reduces the initial entanglement regardless of whether the detectors are in the same or opposite Rindler wedges.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Review
Physics, Particles & Fields
K. G. Arun, Enis Belgacem, Robert Benkel, Laura Bernard, Emanuele Berti, Gianfranco Bertone, Marc Besancon, Diego Blas, Christian G. Bohmer, Richard Brito, Gianluca Calcagni, Alejandro Cardenas-Avendano, Katy Clough, Marco Crisostomi, Valerio De Luca, Daniela Doneva, Stephanie Escoffier, Jose Maria Ezquiaga, Pedro G. Ferreira, Pierre Fleury, Stefano Foffa, Gabriele Franciolini, Noemi Frusciante, Juan Garcia-Bellido, Carlos Herdeiro, Thomas Hertog, Tanja Hinderer, Philippe Jetzer, Lucas Lombriser, Elisa Maggio, Michele Maggiore, Michele Mancarella, Andrea Maselli, Sourabh Nampalliwar, David Nichols, Maria Okounkova, Paolo Pani, Vasileios Paschalidis, Alvise Raccanelli, Lisa Randall, Sebastien Renaux-Petel, Antonio Riotto, Milton Ruiz, Alexander Saffer, Mairi Sakellariadou, Ippocratis D. Saltas, B. S. Sathyaprakash, Lijing Shao, Carlos F. Sopuerta, Thomas P. Sotiriou, Nikolaos Stergioulas, Nicola Tamanini, Filippo Vernizzi, Helvi Witek, Kinwah Wu, Kent Yagi, Stoytcho Yazadjiev, Nicolas Yunes, Miguel Zilhao, Niayesh Afshordi, Marie-Christine Angonin, Vishal Baibhav, Enrico Barausse, Tiago Barreiro, Nicola Bartolo, Nicola Bellomo, Ido Ben-Dayan, Eric A. Bergshoeff, Sebastiano Bernuzzi, Daniele Bertacca, Swetha Bhagwat, Beatrice Bonga, Lior M. Burko, Geoffrey Compere, Giulia Cusin, Antonio da Silva, Saurya Das, Claudia de Rham, Kyriakos Destounis, Ema Dimastrogiovanni, Francisco Duque, Richard Easther, Hontas Farmer, Matteo Fasiello, Stanislav Fisenko, Kwinten Fransen, Jorg Frauendiener, Jonathan Gair, Laszlo Arpad Gergely, Davide Gerosa, Leonardo Gualtieri, Wen-Biao Han, Aurelien Hees, Thomas Helfer, Jorg Hennig, Alexander C. Jenkins, Eric Kajfasz, Nemanja Kaloper, Vladimir Karas, Bradley J. Kavanagh, Sergei A. Klioner, Savvas M. Koushiappas, Macarena Lagos, Christophe Le Poncin-Lafitte, Francisco S. N. Lobo, Charalampos Markakis, Prado Martin-Moruno, C. J. A. P. Martins, Sabino Matarrese, Daniel R. Mayerson, Jose P. Mimoso, Johannes Noller, Nelson J. Nunes, Roberto Oliveri, Giorgio Orlando, George Pappas, Igor Pikovski, Luigi Pilo, Geraint Pratten, Tomislav Prokopec, Hong Qi, Saeed Rastgoo, Angelo Ricciardone, Rocco Rollo, Diego Rubiera-Garcia, Olga Sergijenko, Stuart Shapiro, Deirdre Shoemaker, Alessandro Spallicci, Oleksandr Stashko, Leo C. Stein, Gianmassimo Tasinato, Andrew J. Tolley, Elias C. Vagenas, Stefan Vandoren, Daniele Vernieri, Rodrigo Vicente, Toby Wiseman, Valery Zhdanov, Miguel Zumalacarregui
Summary: This white paper summarizes the importance of LISA in the field of fundamental physics and discusses future research directions and connections with other working groups.
LIVING REVIEWS IN RELATIVITY
(2022)
Review
Astronomy & Astrophysics
Krishnakanta Bhattacharya, Bibhas Ranjan Majhi
Summary: In this review, the features of scalar-tensor gravity, including thermodynamics and the fluid-gravity correspondence, as well as the issue of conformally connected frames, have been rigorously studied and summarized.
GENERAL RELATIVITY AND GRAVITATION
(2022)
Article
Astronomy & Astrophysics
Saraswati Devi, S. Abhinove Nagarajan, Sayan Chakrabarti, Bibhas Ranjan Majhi
Summary: This paper focuses on the shadow calculation of the recently proposed AOS black hole in loop quantum gravity. The rotating solution of the originally proposed static AOS black hole is constructed using the modified Newman-Janis algorithm. The effects of quantum gravity on the shadows of both non-rotating and rotating loop quantum black hole solutions are studied, revealing a contraction in shadow radius due to quantum effects. The super-radiance condition in the rotating AOS background is found to be similar to the Kerr case, with a larger rotation compared to Kerr in the low mass regime.
PHYSICS OF THE DARK UNIVERSE
(2023)
Article
Astronomy & Astrophysics
Abhinove Nagarajan Seenivasan, Sayan Chakrabarti, Bibhas Ranjan Majhi
Summary: We revisit the thermodynamic description of a fluid in scalar-tensor gravity theory and propose a general approach to study the thermodynamics of relativistic fluids. By using an equivalent description of gravitational dynamics in both Jordan and Einstein frames, we identify the energy-momentum tensors for the scalar fluid as that of an ideal fluid. We also point out issues with using Eckart's formalism for an ideal fluid and suggest a possible alternative description valid for a general ideal fluid.
Article
Astronomy & Astrophysics
Dipankar Barman, Angshuman Choudhury, Bhushan Kad, Bibhas Ranjan Majhi
Summary: Two entangled two-level Unruh-DeWitt detectors, when at least one of them is not isolated from the environment quantum fields, spontaneously lose entanglement. The eternal interaction between the detectors and environment leads to spontaneous emission from the detectors' excited states and vacuum fluctuations of the field, resulting in a decrease in communication between the entangled qubits during their free fall towards the black hole horizon.
Article
Astronomy & Astrophysics
Dipankar Barman, Bibhas Ranjan Majhi
Summary: This study focuses on quantum entanglement harvesting in a relativistic setup and explores the generation of entanglement between two uniformly accelerated detectors with reflecting boundaries. The study finds that the reflecting boundaries can both suppress and enhance entanglement, and increasing the boundaries has a significant impact on the phenomenon.
Article
Astronomy & Astrophysics
Dipankar Barman, Subhajit Barman, Bibhas Ranjan Majhi
Summary: In recent times, entanglement harvesting from the quantum field has been extensively studied in flat and different curved backgrounds. Our work presents a comprehensive formulation to achieve entanglement harvesting from nonvacuum background fluctuations. The findings reveal that entanglement harvesting is suppressed compared to vacuum fluctuations in this situation.
Correction
Physics, Particles & Fields
Saurya Das, Mitja Fridman, Gaetano Lambiase, Antonio Stabile, Elias C. Vagenas
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Physics, Particles & Fields
Saurya Das, Mitja Fridman, Gaetano Lambiase, Antonio Stabile, Elias C. Vagenas
Summary: The EDGES collaboration has reported an important result on the absorption signal in the Cosmic Microwave Background radiation spectrum, which deviates from the predictions of the standard cosmology model. The researchers explore the possibility of explaining this anomaly using modified dispersion relations.
EUROPEAN PHYSICAL JOURNAL C
(2022)
