Related papers: Partons and Black Holes
We examine the real-time dynamics of a system of one or more black holes interacting with long wavelength gravitational fields. We find that the (classical) renormalizability of the effective field theory that describes this system…
We investigate photon signatures of general decaying dark-matter particles in halos of primordial black holes. We derive the halo-profile density and the total decay rate for these combined dark-matter scenarios. For the case of axion-like…
Astrophysical black holes are likely to be surrounded by various forms of matter in the form of disks or halos. While a number of studies have examined the impact of an environment on the lensing of light or gravitational waves from…
In this note, we consider particle falling in the black hole with an additional potential. Following the proposal by Susskind \cite{Susskind:2018tei}, we study the growth rate of the particle's Rindler momentum, which corresponds to the…
Aspects of holography or dimensional reduction in gravitational physics are discussed with reference to black hole thermodynamics. Degrees of freedom living on Isolated Horizons (as a model for macroscopic, generic, eternal black hole…
A non-singular black hole solution is briefly presented which violates energy conditions only at its interior by postulating a consistent shift to negative energies and gravitationally repulsive negative masses at the event horizon. This…
A two-dimensional dilatonic black hole induced by a topological soliton is exactly solvable in the scalar field theory coupled to dilaton gravity. The Hawking radiation of the black hole is studied in the one-loop approximation with the…
Hawking's prediction of black-hole evaporation depends on the application of known physics to fantastically high energies -- well beyond the Planck scale. Here, I show that before these extreme regimes are reached, another physical effect…
A new simple and general explanation of the effect of acceleration of particles by black holes to infinite energies in the centre of mass frame is suggested. It is based on kinematics of particles moving near the horizon. This effect arises…
We show that transient resonances occur in the two body problem in general relativity, in the highly relativistic, extreme mass-ratio regime for spinning black holes. These resonances occur when the ratio of polar and radial orbital…
The influence of a possible low gravity scale, concretely through the presence of extra dimensions or additional species, on radiation properties of micro black holes is investigated. In particular, the suppression of evaporation through…
Approximating light charged point-like particles in terms of (nonextremal) dilatonic black holes is shown to lead to certain pathologies in Planckian scattering in the eikonal approximation, which are traced to the presence of a (naked)…
In the semi-classical treatment, i.e. in a classical black hole geometry, Hawking quanta emerge from trans-Planckian configurations because of scale invariance. There is indeed no scale to stop the blue-shifting effect encountered in the…
Primordial black holes (PBHs) are a useful tool in cosmology to probe primordial inhomogeneities on small scales that reenter the Hubble radius during the radiation dominated epoch. In this paper, a phenomenon we call the double formation…
The mechanisms which give rise to Hawking radiation are revealed by analyzing in detail pair production in the presence of horizons. In preparation for the black hole problem, three preparatory problems are dwelt with at length: pair…
According to 't Hooft the combination of quantum mechanics and gravity requires the three dimensional world to be an image of data that can be stored on a two dimensional projection much like a holographic image. The two dimensional…
We study the tunneling of massless scalars across black hole horizons in any number of spacetime dimensions greater than three. Our analysis finds that corrections due to backreaction and the inverse dimensional expansion are naturally…
A promising strategy for better understanding space and time at the Planck scale, is outlined and further pursued. It is explained in detail, how black hole unitarity demands the existence of transformations that can remove firewalls. This…
Recent astronomical data on Black hole observations are reviewed. The arguments in favor that the observed black holes are predominantly primordial (PBH) are presented. The mass spectrum of PBH is best fit to the log-normal one. A model of…
Extremal black holes are studied in a two dimensional model motivated by a dimensional reduction from four dimensions. Their quantum corrected geometry is calculated semiclassically and a mild singularity is shown to appear at the horizon.…