Related papers: Vacuum Polarisation and the Black Hole Singularity
The formation and evaporation of small AdS black holes in a theory with a holographic dual is governed by the usual rules of quantum mechanics. The eigenstate thermalization hypothesis explains the validity of semiclassical gravity for…
In this paper, we investigate the dynamical formation and evolution of 2 + 1-dimensional charged black holes. We numerically study dynamical collapses of charged matter fields in an anti de Sitter background and note the formation of black…
We study causality constraints on black hole thermodynamics in nonlinear electrodynamics, where the Lagrangian is taken to be an arbitrary function of the electromagnetic field strength tensor. By requiring the absence of superluminal…
Classically, the inner horizon of a perturbed, rotating black hole undergoes an instability known as mass inflation, wherein the spacetime curvature diverges as a result of hyper-relativistic crossing streams of ingoing and outgoing…
We demonstrate the power of the black hole mass gap as a novel probe of fundamental physics. New light particles that couple to the Standard Model can act as an additional source of energy loss in the cores of population-III stars,…
Polymer quantization is a non-standard representation of the quantum mechanics that inspired by loop quantum gravity. To study the associated statistical mechanics, one needs to find microstates' energies which are eigenvalues of the…
We propose that black holes are \emph{soliton-esque} objects, where gravitational collapse is balanced by quantum vacuum dispersion, modeled via \(R+\alpha R^{2}\) gravity. Classical singularities are replaced by oscillating, finite-radius…
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…
We prove a singularity theorem in semiclassical gravity without assuming global hyperbolicity or the null energy/curvature condition; the former is replaced by the weaker causality conditions of stable causality and past reflectivity, and…
We consider the spacetimes corresponding to static Global Monopoles with interior boundaries corresponding to a Black Hole Horizon and analyze the behavior of the appropriate ADM mass as a function of the horizon radius r_H. We find that…
Black hole entropy is studied for an exactly solvable model of two-dimensional gravity\cite{rst1}, using recently developed Noether charge techniques\cite{wald1}. This latter approach is extended to accomodate the non-local form of the…
Recently, it has been claimed that the back reaction of vacuum polarization on a black hole spacetime naturally regularizes infinities in the black hole entropy. We examine the back reaction calculation and find no such short-distance…
Semi-classical corrections at large curvature are employed in toy models of spherically symmetric gravitational collapse in order to avoid the formation of singularities. The resulting spacetimes may produce bounces, compact remnants or…
I present a very simplistic toy model for the inflationary paradigm where the size of the universe undergoes a period of exponential growth. The basic assumption I make use of is that black holes might have a quantized area (mass) spectrum…
Primordial black holes may arise through ultra slow-roll inflation. In this work we study a toy model of ultra slow-roll inflation with a shallow dip. The ultra slow-roll stage enhances the curvature perturbations and thus the primordial…
We study the effect of supergravity corrections due to a linear and a bilinear term in the K\"ahler potential, in the context of a supersymmetric hybrid inflation model. By appropriate choice of the parameters associated to these terms, we…
We investigate the massless scalar field perturbations, including the quasinormal mode spectrum and the ringdown waveform, of a regular black hole spacetime that was derived via the Loop Quantum Gravity inspired polymer quantization of…
We calculate the Euclidean propagator for a conformally coupled massless scalar field in the background of the three-dimensional black hole. The expectation value $\langle\varphi^2\rangle$ in the Hartle-Hawking state is obtained in the…
The accretion disk around a black hole and its emissions play an essential role in theoretical analysis of the black hole image. In the literature, two analytical toy models of accretions are widely adopted: the spherical model and the thin…
We develop in this thesis the principles governing the production of our universe's primordial inhomogeneities during its early phase of inflation. As a guiding thread we ask what physics during inflation can lead to perturbations so large…