Article
Astronomy & Astrophysics
Tieguang Zi, Ziqi Zhou, Hai-Tian Wang, Peng-Cheng Li, Jian-dong Zhang, Bin Chen
Summary: We derive approximate analytic-kludge waveforms for the inspiral of a charged stellar-mass compact object into a charged massive Kerr-Newman black hole. The modifications of the inspiral orbit due to charges in this system are caused by electric force, dipole electromagnetic radiation, and metric deformation. These effects are encoded in the fundamental frequencies of the orbits, calculated analytically in the weak-field regime. By comparing waveforms with and without charges, we show that even tiny charges can produce distinct imprints. Parameter estimation for charges using the Fisher information matrix method yields precision at the level of 10-5 in suitable scenarios.
Article
Astronomy & Astrophysics
Hai-Tian Wang, Shao-Peng Tang, Peng-Cheng Li, Yi-Zhong Fan
Summary: An analytical ringdown waveform model has been developed for charged black holes, which was precise enough to analyze gravitational wave data such as GW150914. The study constrained the charge to mass ratio of the remnant black hole and the deviation parameter of scalar-tensor vector gravity with the ringdown gravitational wave data for the first time. This approach can be applied to other binary black hole mergers with loud ringdown radiation.
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
Astronomy & Astrophysics
Zhao Li, Jin Qiao, Wen Zhao, Er Xinzhong
Summary: In this study, we calculate the gravitational Faraday rotation angle of gravitational waves in the weak deflection limit, assuming it is lensed by a Kerr black hole. We find that this rotation effect alters the initial polarization state of the lensed gravitational waves, which depends on the light-of-sight component of the black hole's angular momentum.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Susanna Barsanti, Nicola Franchini, Leonardo Gualtieri, Andrea Maselli, Thomas P. Sotiriou
Summary: This study focuses on extreme mass ratio inspirals in binary systems with a new fundamental scalar field. By simplifying the model drastically, the impact of scalar charge on orbital evolution is examined for eccentric equatorial orbits, with an assessment of LISA's capability to detect or constrain the scalar charge.
Article
Astronomy & Astrophysics
Alex Simpson, Matt Visser
Summary: In this study, a highly tractable non-singular modification of the Kerr geometry, known as the eye of the storm, is analyzed in detail. The physics in this spacetime becomes extraordinarily manageable compared to similar candidates in the literature, making it suitable for straightforward extraction of astrophysical observables falsifiable or verifiable by the experimental community.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Pedro Henrique Croti Siqueira, Mauricio Richartz
Summary: In this article, we use the continued fraction method to determine the eigenfrequencies of a scalar field around a Kerr-like black hole and explore the effects of a deformation parameter on the quasinormal modes and quasibound states. We calculate the timescales associated with the superradiant instabilities of the scalar field and discuss the properties of stationary scalar clouds that may be formed by these instabilities.
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.
Article
Astronomy & Astrophysics
Hong Guo, Yunqi Liu, Chao Zhang, Yungui Gong, Wei-Liang Qian, Rui-Hong Yue
Summary: We study extreme mass ratio inspirals in modified gravity, modeling a system where a small compact object with scalar charge spirals into a supermassive Kerr black hole. Besides tensorial gravitational waves, radiation is induced by the scalar field. By investigating the dependence of observables on specific spacetime configurations, we find that the presence of additional scalar emission leads to a more significant rate of overall energy loss and has a greater impact on the gravitational radiation produced by a central black hole with higher spin, indicating the possibility of detecting the scalar charge.
Article
Astronomy & Astrophysics
Misba Afrin, Rahul Kumar, Sushant G. Ghosh
Summary: The study reveals that the size and shape of hairy Kerr black holes are influenced by the parameter l(0), resulting in more distorted shadows compared to Kerr black holes. Estimating the parameters associated with hairy Kerr black holes through the investigation of ergosphere and shadows provides insights into the differences between these black holes.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
H. Garcia-Compean, V. S. Manko, C. J. Ramirez-Valdez
Summary: Using the concept of thermodynamic length, the first law of thermodynamics for two equal mass Kerr-Newman black holes separated by a massless strut was consistently derived. The expression of the free energy for two generic Kerr-Newman black holes was also proposed in this study.
Article
Astronomy & Astrophysics
Saumya Ghosh, Subhajit Barman
Summary: The paper discusses the phenomenon of extremal black holes not emitting Hawking radiation, explores reproducing the vanishing number density of Hawking quanta using canonical formulation, and studies the significance of the relationship between spatial near-null coordinates for the Hawking effect.
Article
Astronomy & Astrophysics
Guansheng He, Wenbin Lin
Summary: This paper systematically investigates the gravitational lensing of relativistic neutral massive particles caused by a Kerr-Newman black hole in the weak-field limit. Analytical expressions for the observable properties of the lensed images are derived and corrections induced by the initial velocity deviation are achieved. The application to the supermassive black hole Sagittarius A* is also analyzed.
Article
Astronomy & Astrophysics
Naritaka Oshita
Summary: We observe destructive interference among Kerr overtones in the early ringdown of a massive black hole merger, and find that the ringdown spectrum follows the Fermi-Dirac distribution. By numerical calculations, we investigate the spectral amplitude of gravitational waves induced by a particle falling into a Kerr black hole, and study the excitation of multiple quasi-normal modes. The results show that the start time of ringdown corresponds to when the particle passes the photon sphere before the strain peak of the signal.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Rafael F. Aranha, Carlos E. M. Cedeno, Rodrigo Maier, Ivano Damiao Soares
Summary: In this study, the spacetime of a boosted Bondi-Sachs rotating black hole is used as a background to examine electromagnetic configurations connected to analytic solutions of Maxwell equations. The Kerr-Schild form is employed to construct zero angular momentum observers (ZAMOs) and evaluate the components of the electric and magnetic fields. Nonsingular patterns of momentum-energy emission in a boosted Kerr-Schild black hole are investigated with varying boost parameters, extending the analysis to consider electromagnetic emission in the framework of a rotating boosted black hole moving at relativistic speeds. Possible mechanisms resembling magnetospheres of rotating boosted black holes are discussed, including the generation of hydromagnetic flows from accretion discs and the production of jets.
Article
Astronomy & Astrophysics
Harvey S. Reall, Norihiro Tanahashi, Benson Way
Article
Astronomy & Astrophysics
Marcello Ortaggio, Vojtech Pravda, Alena Pravdova, Harvey S. Reall
CLASSICAL AND QUANTUM GRAVITY
(2012)
Article
Astronomy & Astrophysics
Vitor Cardoso, Leonardo Gualtieri, Carlos Herdeiro, Ulrich Sperhake, Paul M. Chesler, Luis Lehner, Seong Chan Park, Harvey S. Reall, Carlos F. Sopuerta, Daniela Alic, Oscar J. C. Dias, Roberto Emparan, Valeria Ferrari, Steven B. Giddings, Mahdi Godazgar, Ruth Gregory, Veronika E. Hubeny, Akihiro Ishibashi, Greg Landsberg, Carlos O. Lousto, David Mateos, Vicki Moeller, Hirotada Okawa, Paolo Pani, M. Andy Parker, Frans Pretorius, Masaru Shibata, Hajime Sotani, Toby Wiseman, Helvi Witek, Nicolas Yunes, Miguel Zilhao
CLASSICAL AND QUANTUM GRAVITY
(2012)
Article
Astronomy & Astrophysics
Harvey S. Reall, Alexander A. H. Graham, Carl P. Turner
CLASSICAL AND QUANTUM GRAVITY
(2013)
Article
Astronomy & Astrophysics
Oscar J. C. Dias, Harvey S. Reall
CLASSICAL AND QUANTUM GRAVITY
(2013)
Article
Astronomy & Astrophysics
Keiju Murata, Harvey S. Reall, Norihiro Tanahashi
CLASSICAL AND QUANTUM GRAVITY
(2013)
Article
Astronomy & Astrophysics
Harvey S. Reall, Norihiro Tanahashi, Benson Way
CLASSICAL AND QUANTUM GRAVITY
(2014)
Review
Astronomy & Astrophysics
Harvey S. Reall
INTERNATIONAL JOURNAL OF MODERN PHYSICS D
(2012)
Article
Astronomy & Astrophysics
Mahdi Godazgar, Harvey S. Reall
Article
Physics, Particles & Fields
Gabriel Bernardi de Freitas, Harvey S. Reall
JOURNAL OF HIGH ENERGY PHYSICS
(2014)
Article
Physics, Mathematical
Harvey S. Reall, Claude M. Warnick
Summary: This paper addresses how to make sense of the equations of motion in effective field theory (EFT) and whether they provide a good approximation to the classical UV theory. The authors propose an approach to solving EFTs and rigorously derive the corresponding EFT for a specific choice of UV theory. They show that a large class of classical solutions to the UV theory are well approximated by EFT solutions.
JOURNAL OF MATHEMATICAL PHYSICS
(2022)
Article
Astronomy & Astrophysics
Iain Davies, Harvey S. Reall
Summary: This paper investigates the well-posedness of the initial value problem for the modified Einstein-Maxwell theory. By employing field redefinitions and a modified harmonic gauge condition, the authors show that the initial value problem is well-posed when the higher derivative corrections to the equations of motion are small.
Article
Astronomy & Astrophysics
Harvey S. Reall
Summary: This paper explores diffeomorphism invariant theories of gravity coupled to matter, focusing on second order equations of motion. It delves into specific theories such as Einstein-Maxwell and Einstein-scalar field theory, demonstrating how causality is governed by characteristic polynomials and identifying surfaces analogous to Fresnel surfaces in crystal optics. It also discusses the implications of Killing horizons and the zeroth law of black hole mechanics in these theories.
Article
Physics, Particles & Fields
James Lucietti, Keiju Murata, Harvey S. Reall, Norihiro Tanahashi
JOURNAL OF HIGH ENERGY PHYSICS
(2013)