Related papers: Do microscopic stable black holes contribute to da…
The evaporation of primordial black holes (PBH) with masses ranging from $\sim 10^{-1}$ to $\sim 10^9$ g could have generated the whole observed dark matter (DM) relic density. It is typically assumed that after being produced, its…
In this short paper we discuss the possibility of testing the nature of astrophysical black holes using the recently observed black hole mergers. We investigate the possibility that a secondary black hole is created in the merger of two…
Models of superdense star clusters at the center of galaxies are investigated to see whether such objects can be stable and long-lived based on evaporation and collision time-scales and stability criteria. We find that physically reasonable…
We study the evaporation of black holes in space-times with extra dimensions of size L. We first obtain a description which interpolates between the expected behaviors of very large and very small black holes and then show that the…
In models with ``large'' and/or warped extra dimensions, the higher-dimensional Planck scale may be as low as a TeV. In that case black holes with masses of a few TeV are expected to be produced copiously in multi-TeV collisions, in…
Black hole spectroscopy is an important pillar when studying gravitational waves from black holes and enables tests of general relativity. Most of the gravitational-wave signals observed over the last decade originate from binary black hole…
Primordial black holes in the solar mass range are a possibly significant component of dark matter. We show how an argument relating the deflection of light by such black holes in the density spike likely to exist around the M87…
Vilkovisky has claimed to have solved the black hole backreaction problem and finds that black holes lose only ten percent of their mass to Hawking radiation before evaporation ceases. We examine the implications of this scenario for cold…
We show that asymptotically de Sitter black holes of negative mass can exist in Lovelock gravity. Such black holes have horizon geometries with non-constant curvature and are known as Exotic Black Holes. We explicitly examine the case of…
Over the past 15 years models with large extra space-time dimensions have been extensively studied. We have learned from these models that the energy scale of quantum gravity may be many orders of magnitude smaller than the conventional…
Black holes with masses $\approx 1\, M_{\odot}$ cannot be produced via stellar evolution. A popular scenario of their formation involves transmutation of neutron stars - by accumulation of dark matter triggering gravitational collapse in…
A dark matter overdensity around a black hole may significantly alter the dynamics of the black hole's merger with another compact object. We consider here intermediate mass-ratio inspirals of stellar-mass compact objects with…
It has been suggested for a long time that dark matter would form a density spike around a black hole. However, no promising evidence has been observed so far to verify this theoretical suggestion. Here, we report the existence of a dark…
The relativistic accretion rate of dark matter by a black hole is revisited. Under the assumption that the phase space density indicator, $Q=\rho_{\infty}/\sigma^3_{\infty}$, remains constant during the inflow, the derived accretion rate…
We perform fully relativistic simulations of the head-on collisions between intermediate-mass black holes and very massive stars. Such collisions are expected to occur in dense stellar clusters and may play an important role in growing the…
We study the effects of the presence of the tachyon field around the black hole. We show that in presence of the tachyon field, unlike the ordinary canonical scalar field, the time evolution of the black hole mass depends on the potential…
In a recent work we have argued that nosy energy momentum diffusion due to space-time discreteness at the Planck scale (naturally expected to arise from quantum gravity) can be responsible for the generation of a cosmological constant…
We investigate the impact of millicharged particles (MCPs) on massive stars undergoing pulsational pair-instability supernovae and on the location of the lower edge of the black hole mass gap. We find that energy losses due to MCP emission…
Black holes in General Relativity are described by space-time metrics that are simpler in comparison to non-vacuum compact objects. However, given the universality of the gravitational pull, it is expected that dark matter accumulates…
We study the evolution of heavy stars ($M\ge40{\rm M}_\odot$) undergoing pair-instability in the presence of annihilating dark matter. Focusing on the scenario where the dark matter is in capture-annihilation equilibrium, we model the…