Article
Physics, Particles & Fields
Sohan Kumar Jha, Anisur Rahaman
Summary: The study explores Lorentz violation in the bumblebee gravity model and its effects on shadow features and radiation emission rate in rotating black hole spacetime.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Physics, Particles & Fields
Furkat Sarikulov, Farruh Atamurotov, Ahmadjon Abdujabbarov, Bobomurat Ahmedov
Summary: A detailed study of the horizon structure and shadow of a Kerr-like black hole is conducted. By analyzing the trajectory of light rays and the effective potential of photons around Kerr-like black holes, the formation of the black hole shadow is investigated. The influence of plasma on the shadow of the black hole and the observable radius and oblateness of the shadow are also explored.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Physics, Multidisciplinary
Hui-Min Wang, Shao-Wen Wei
Summary: This paper tests the Lorentz symmetry in Einstein-bumblebee gravity by observing the shadow of a Kerr-like black hole with or without plasma. The results show a nonmonotonic behavior of the shadow radius with the Lorentz-violating parameter. Three additional distortion observables are calculated and found to increase with the Lorentz-violating parameter. The impact of the Lorentz-violating parameter on the deflection angle of light rays and the motion of photons in a plasma are also analyzed.
EUROPEAN PHYSICAL JOURNAL PLUS
(2022)
Article
Astronomy & Astrophysics
Rui Jiang, Rui-Hui Lin, Xiang-Hua Zhai
Summary: In this paper, the authors investigate the superradiant instability of a Kerr-like black hole under the perturbation of a massive scalar field in an Einstein-bumblebee gravity model. The study shows that the Lorentz breaking parameter L affects the bound state spectrum and superradiance, even though it does not impact the superradiance regime or the regime of the bound states. Comparing with the Kerr black hole, the superradiant instability of this black hole is impacted by not only the rotation parameter and the product of the black hole mass and the field mass, but also the Lorentz breaking parameter. Through calculations, the most unstable mode is found to occur at specific parameter values with a maximum growth rate of the field that is about 10 times higher than that in the Kerr black hole.
Article
Astronomy & Astrophysics
Edgardo Franzin, Stefano Liberati, Mauro Oi
Summary: Recent tests of gravity in the strong-field regime have shown agreement with general relativity, particularly in the case of black holes consistent with the Kerr spacetime. However, small detectable deviations are still possible due to statistical errors in current observations. A study on the superradiance of scalar and electromagnetic test fields around Kerr-like black holes reveals that superradiance is highly suppressed for large deformation parameters but can be greater than Kerr for small ones. Initial results on the superradiant instability of these non-Kerr spacetimes against massive scalar fields have also been provided.
Article
Physics, Particles & Fields
Sara Kanzi, Izzet Sakalli
Summary: In the context of Lorentz symmetry breaking (LSB), the quasinormal modes (QNM) and greybody factors (GF) of the Kerr-like black hole spacetime from the bumblebee gravity model are investigated. Scalar and fermionic perturbations are analyzed using both semi-analytic WKB method and the time domain approach. The impact of LSB on the bosonic/fermionic QNM and GF of the Kerr-like black hole are examined in detail, with results depicted graphically and discussed.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Physics, Particles & Fields
S. N. Sajadi, S. H. Hendi
Summary: This work introduces analytical approximate black hole solutions in Einstein-Cubic gravity. The near horizon and asymptotic solutions are constructed as the first step to obtain complete solutions. The approximate analytic solutions are then obtained through continued-fraction expansion. The thermodynamic quantities are also computed, and the analytic solutions for near horizon quantities are obtained using the first law and Smarr formula. Finally, the same approach is used to obtain new static black hole solutions with different metric functions.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Editorial Material
Physics, Particles & Fields
R. Maluf, C. R. Muniz
Summary: The paper investigates the greybody radiation and quasinormal modes of Kerr-like black holes in the Bumblebee gravity model, but is found to be based on an incorrect result obtained in a previous study.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Astronomy & Astrophysics
Asanka Amarasinghe, Tianye Liu, Daniel A. Norman, Philip D. Mannheim
Summary: This paper investigates cosmological perturbation theory in the context of the fourth-order derivative conformal gravity theory and provides an exact solution from the recombination era until the present era.
Article
Astronomy & Astrophysics
G. G. L. Nashed
Summary: This research integrates an axionic field into the context of dynamical Chern-Simons gravity and explores the characteristics of a slowly rotating black hole within this theoretical framework. It is the first study to tackle this problem within the context of gravitational theory coupled with the axionic field. The investigation demonstrates the explicit expression of the enigmatic function U and reveals its potentials in generating significantly potent Chern-Simons black holes.
Article
Physics, Particles & Fields
Sohan Kumar Jha, Anisur Rahaman
Summary: This study investigates a bumblebee gravity-based Kerr-like black hole in a noncommutative background, analyzing the superradiance effect and black hole shadow. The study reveals the impact of Lorentz violating parameter and NC parameter on the superradiance effect and shadow, attempting to constrain the NC parameters using data from the Event Horizon Telescope collaboration. The findings suggest that black holes associated with NC Kerr-like spacetime may present suitable candidates for astrophysical black holes.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Astronomy & Astrophysics
Riasat Ali, Kazuharu Bamba, Syed Asif Ali Shah, Muhammad Junaid Saleem
Summary: In this study, the Hamilton-Jacobi ansatz is utilized to analyze the tunneling of boson charged particles in Rastall gravity Kerr-Newman black holes surrounded by perfect fluid matter through the horizon. The influence of geometric black hole parameters on radiation is examined using Lagrangian gravity equation, with a focus on the effects of quantum gravity on the corrected Hawking temperature. Graphical analysis is applied to investigate the impact of Rastall gravity black holes surrounded by perfect fluid matter on Hawking radiation, as well as the stability and instability of these black holes, and the influence of quantum gravity and rotation parameters on black hole radiation.
INTERNATIONAL JOURNAL OF MODERN PHYSICS D
(2022)
Article
Astronomy & Astrophysics
Marc Mars, Carlos Peon-Nieto
Summary: By using the asymptotic characterization results of spacetimes at conformal infinity, this study proves the one-to-one correspondence between Kerr-Schild-de Sitter spacetimes and spacetimes in the Kerr-de Sitter-like class with conformally flat I.
Article
Physics, Nuclear
V. M. Khatsymovsky
Summary: This paper continues the study of black holes in the Regge calculus framework, focusing on the discrete Kerr-Newman-type solution. By integrating over the connection, the classical solution with a certain edge length scale emerges as an optimal starting point for perturbative expansion. The paper investigates the electromagnetic contribution to the metric and curvature on the singularity ring, finding that it is infinitely greater than the contribution of the delta-function-like mass distribution.
INTERNATIONAL JOURNAL OF MODERN PHYSICS A
(2023)
Article
Physics, Multidisciplinary
Izzet Sakalli, Esra Yoruk
Summary: This article studies the Hawking radiation of Schwarzschild black hole within the bumblebee gravity model. By introducing alternative coordinate systems and incorporating the Generalized Uncertainty Principle, the dependency of Hawking radiation temperature on coordinate systems is examined. The modified equation characterizing particle behavior near the event horizon is derived, and the modified temperature of the SBHBGM is obtained by calculating the tunneling probability using the modified action.
Article
Physics, Particles & Fields
Sohan Kumar Jha, Anisur Rahaman
Summary: The study explores Lorentz violation in the bumblebee gravity model and its effects on shadow features and radiation emission rate in rotating black hole spacetime.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Astronomy & Astrophysics
Sohan Kumar Jha, Himangshu Barman, Anisur Rahaman
Summary: This study focuses on the metric and particle motion in the bumblebee gravity model, finding that the perihelion shift obtains a generalized expression in this model, and the revolution period is affected by a Lorentz violating factor in general. The parameters used can be constrained with a similar conjecture as before.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Himangshu Barman, Anisur Rahaman, Sohan Kumar Jha
Summary: The Thomas-Fermi model is used to capture the Planck-scale effect by generalizing the uncertainty relation with linear and quadratic terms of momentum. The model is reformulated for both non-relativistic and relativistic cases, studying the dialectic screening and explicitly finding the Fermi length in each case.
MODERN PHYSICS LETTERS A
(2021)
Article
Astronomy & Astrophysics
Sahazada Aziz, Sohan Kumar Jha, Anisur Rahaman
Summary: This study investigates a specific f(R) model with multiple higher-order terms in the cosmic inflation scenario, finding that under certain conditions, it leads to a viable inflationary model which aligns well with recent Planck results.
CLASSICAL AND QUANTUM GRAVITY
(2021)
Article
Physics, Multidisciplinary
Himangshu Barman, Sohan Kumar Jha, Anisur Rahaman
Summary: This study examines the thermodynamic properties of a Schwarzschild black hole surrounded by quintessence matter using a generalized Heisenberg algebra with quadratic and linear terms in momentum. The temperature, heat capacity, and entropy associated with the black hole are computed using this modified algebra. The behavior of the isotherms for this black hole is also studied. The results show that the modified algebra indicates a remnant of the black hole, which could be a plausible solution to the information loss problem.
EUROPEAN PHYSICAL JOURNAL PLUS
(2022)
Article
Physics, Multidisciplinary
Sohan Kumar Jha, Anisur Rahaman
Summary: We study the hairy Schwarzschild black hole that evades the no-hair theorem by considering additional sources from the surroundings, namely dark matter with a constant energy-momentum tensor. The presence of hair is characterized by the parameter l(0). In the background of the hairy Schwarzschild black hole, we observe that the lensing coefficient a increases with deviation parameter alpha, but decreases with the primary hair l(0). However, the opposite effect is observed for the lensing coefficient b and the impact parameter bm. Finally, we briefly discuss the weak gravitational lensing in the background of the hairy Schwarzschild black hole using the Gauss-Bonnet theorem.
EUROPEAN PHYSICAL JOURNAL PLUS
(2023)
Article
Astronomy & Astrophysics
Sohan Kumar Jha, Mohsen Khodadi, Anisur Rahaman, Ahmad Sheykhi
Summary: In this paper, we perform a semiclassical analysis of the superradiance phenomenon for a rotating hairy Horndeski black hole. We find that the addition of the hairy parameter enhances the superradiance scattering and its frequency range compared to the Kerr black hole. Furthermore, we analyze the superradiant instability of the black hole spacetime against massive scalar fields and conclude that the hairy Horndeski parameter has no influence on the standard superradiant instability regime.
Article
Physics, Particles & Fields
Sohan Kumar Jha, Anisur Rahaman
Summary: This study investigates the geometrical structure and the influence of parameters on the singularity of Kerr-Sen-like black holes, and introduces modified Einstein-bumblebee gravity to explore the role of spontaneous Lorentz violation on superradiance scattering phenomena and associated instability. The study shows that superradiance scattering is enhanced when the Lorentz-violating parameter is negative, and reduced when it is positive.
EUROPEAN PHYSICAL JOURNAL C
(2022)
