Horizon-scale tests of gravity theories and fundamental physics from the Event Horizon Telescope image of Sagittarius A

S Vagnozzi, R Roy, YD Tsai, L Visinelli… - … and Quantum Gravity, 2023 - iopscience.iop.org
Horizon-scale images of black holes (BHs) and their shadows have opened an
unprecedented window onto tests of gravity and fundamental physics in the strong-field …

Charged black hole in 4D Einstein-Gauss-Bonnet gravity: particle motion, plasma effect on weak gravitational lensing and centre-of-mass energy

F Atamurotov, S Shaymatov, P Sheoran… - Journal of Cosmology …, 2021 - iopscience.iop.org
We study the motion of charged and spinning particles and photons in the 4D charged
Einstein-Gauss-Bonnet (EGB) black hole vicinity. We determine the radius of the innermost …

Testing alternative spacetimes by high-frequency quasi-periodic oscillations observed in microquasars and active galactic nuclei

M Shahzadi, M Kološ, R Saleem… - Classical and Quantum …, 2024 - iopscience.iop.org
In this article, we try to capture the influence of deviation from standard Kerr black hole (BH)
spacetime on observed high-frequency quasi-periodic oscillations (QPOs) signal. We …

Testing alternative theories of gravity by fitting the hot-spot data of Sgr A

M Shahzadi, M Kološ, Z Stuchlík, Y Habib - The European Physical …, 2022 - Springer
We are fitting dynamics of electrically neutral hot-spot orbiting around Sagittarius A*(Sgr A*)
source in Galactic center, represented by various modifications of the standard Kerr black …

Motion of charged and spinning particles influenced by dark matter field surrounding a charged dyonic black hole

S Shaymatov, P Sheoran, S Siwach - Physical Review D, 2022 - APS
We investigate the motion of massive charged and spinning test particles around a charged
dyonic black hole surrounded by perfect fluid scalar dark matter field. We obtain the …

Massless polarized particle and Faraday rotation of light in the Schwarzschild spacetime

AA Deriglazov - Physical Review D, 2021 - APS
We present the manifestly covariant Lagrangian of a massless polarized particle that implies
all dynamic and algebraic equations as the conditions of extreme of this variational problem …

Motion of spinning particles around black holes

JM Ladino, CA del Valle, E Larrañaga - ar** conditions
S Liberati, C Pfeifer, J Relancio - Journal of Cosmology and …, 2022 - iopscience.iop.org
The possibility that rotating black holes could be natural particle accelerators has been
subject of intense debate. While it appears that for extremal Kerr black holes arbitrarily high …

Chaotic motion and Periastron precession of spinning test particles moving in the vicinage of a Schwarzschild black hole surrounded by a quintessence matter field

S Giri, P Sheoran, H Nandan, S Shaymatov - The European Physical …, 2023 - Springer
In the present work, our main objective is to investigate the orbits of spinning test particles
around a Schwarzschild black hole under the influence of a quintessence matter field …

[HTML][HTML] An angular rainbow of light from curved spacetime

AA Deriglazov - Physics Letters A, 2022 - Elsevier
We try to go beyond the geometrical optics approximation, by showing that a massless
polarized particle allows a wide class of non minimal interactions with an arbitrary …