Related papers: Testing the Weak Equivalence Principle near black …
Recent implications of results from quantum information theory applied to black holes has led to the confusing conclusions that requires either abandoning the equivalence principle (e.g. the firewall picture), or the no-hair theorem (e.g.…
Accreting binaries containing a black hole are stellar systems composed of a normal star and a black hole. Because of the strong gravitational pull of the black hole, matter is removed from the companion star and falls into the compact ob…
Astrophysical black holes could be nearly extremal (that is, rotating nearly as fast as possible); therefore, nearly extremal black holes could be among the binaries that current and future gravitational-wave observatories will detect.…
In viable models of minicharged dark matter, astrophysical black holes might be charged under a hidden $U(1)$ symmetry and are formally described by the same Kerr-Newman solution of Einstein-Maxwell theory. These objects are unique probes…
This paper evaluates the potential for constraining the quantum scale parameter $\xi$ of regular black hole within the asymptotically safe gravity framework using gravitational waves from extreme mass ratio inspirals (EMRIs). Since $\xi$…
This research delves into the optical characteristics of stationary, spherically symmetric black holes. These black holes follow the Konoplya-Zhidenko deformation rule in arbitrary gravity theories. This research finds that the effects of…
There is a forbidden region in the parameter space of quasinormal modes of black holes in general relativity. Using both inspiral and ringdown phases of gravitational waves from binary black holes, we propose two methods to test general…
The presence of gravity implies corrections to the Einstein-Planck formula $E=h \nu$. This gives hope that the divergent blueshift in frequency, associated to the presence of a black hole horizon, could be smoothed out for the energy. Using…
Charged black holes, both spherically symmetric and rotating, in the low energy limit of string theory (Einstein-Maxwell-dilaton theory) are compared to analogous geometries in pure general relativity. We describe various physical…
We investigate the weak cosmic censorship conjecture (WCCC) violation through the absorption of a charged, rotating test particle by Kerr Newman spacetime in modified gravity (KN MOG). The result is sensitive to multiple factors, including…
In this study, we investigate the Weak Gravity Conjecture (WGC) and Weak Cosmic Censorship Conjecture (WCCC) for a quantum-corrected Reissner-Nordstr\"om Anti-de Sitter (RN-AdS) black hole embedded in Kiselev spacetime. By making small…
The spacetime geometry around astrophysical black holes is well approximated by the Kerr metric, but deviations from standard predictions are possible in a number of scenarios beyond Einstein's gravity and in the presence of exotic matter.…
The potential conflict between the Weak Gravity Conjecture (WGC) and the Weak Cosmic Censorship Conjecture (WCCC) poses a significant challenge in general relativity. The WCCC serves as a fundamental assumption ensuring the coherence of…
We propose and apply a new test of Einstein's Equivalence Principle (EEP) based on the gravitational redshift induced by the central super massive black hole of quasars in the surrounding accretion disk. Specifically, we compare the…
On the premise of the importance of energy conditions for regular black holes, we propose a method to remedy those models that break the dominant energy condition, e.g., the Bardeen and Hayward black holes. We modify the metrics but ensure…
Characterizing the properties of black holes is one of the most important science objectives for gravitational-wave observations. Astrophysical evidence suggests that black holes that are nearly extremal (i.e. spins near the theoretical…
A relativistic model of geometrically thin and optically thick accretion disks is worked out for a class of magnetically charged black holes, which are solutions to the Einstein-Maxwell-dilaton theory with a dilaton-coupled Euler-Heisenberg…
Understanding the dynamics behind black hole state transitions and the changes they reflect in outbursts has become long-standing problem. The X-ray reflection spectrum describes the interaction between the hard X-ray source (the power-law…
Einstein-Maxwell dilaton-axion gravity is a string-inspired model arising from the low energy effective action of heterotic string theory and an important candidate as alternative to General Relativity. Recently, some authors have explored…
The co-evolution of a supermassive black hole with its host galaxy through cosmic time is encoded in its spin. At $z>2$, supermassive black holes are thought to grow mostly by merger-driven accretion leading to high spin. However, it is…