Related papers: Long Strings and Quasinormal Winding Modes
We study worldsheet theory of confining strings in two-dimensional massive adjoint QCD. Similarly to confining strings in higher dimensions this theory exhibits a non-trivial $S$-matrix surviving even in the strict planar limit. In the…
The one-loop contribution to the entropy of a black hole from field modes near the horizon is computed in string theory. It is modular invariant and ultraviolet finite. There is an infrared divergence that signifies an instability near the…
Quasinormal modes of rapidly rotating black holes are crucial in understanding the ringdown phase after a merger. While for Kerr black holes these modes have been known for a long time, their calculation has remained a challenge in…
It is observed that the three-dimensional BTZ black hole is a supersymmetric solution of the low-energy field equations of heterotic string theory compactified on an Einstein space. The solution involves a non-zero dilaton and NS-NS…
We describe a family of twisted partition functions for the relativistic spinning particle models. For suitable choices of fugacities this computes a refined Euler characteristics that counts the dimension of the physical states for…
We explore various aspects of supersymmetric black hole partition functions in four-dimensional toroidally compactified heterotic string theory. These functions suffer from divergences owing to the hyperbolic nature of the charge lattice in…
This PhD thesis mainly deals with deformations of locally anti-de Sitter black holes, focusing in particular on BTZ black holes. We first study the generic rotating and (extended) non-rotating BTZ black holes within a pseudo-Riemannian…
Using the path integral approach, we discuss the correlation functions of the $SL(2,\bfC)/SU(2)$ WZW model, which corresponds to the string theory on the Euclidean $AdS_3$. We obtain the two- and three-point functions for generic primary…
Maggiore observed that, in the high-damping regime, the quasi-normal modes spectrum for the Schwarzschild black hole resembles that of a quantum harmonic oscillator. Motivated by this observation, we describe a black hole as a statistical…
We examine the large volume compactification of Type IIB string theory or its F theory limit and the associated supersymmetry breakdown and soft terms. It is crucial to incorporate the loop-induced moduli mixing, originating from radiative…
We revisit the spectrum of closed strings in the Lorentzian signature 2D black hole in string theory. Using the description of the black hole as a gauged WZNW model, we argue that the spectrum of the closed strings contain states from the…
We have studied the scalar perturbation of static charged dilaton black holes in 2+1 dimensions. The black hole considered here is a solution to the low-energy string theory in 2+1 dimensions. It is asymptotic to the anti-de Sitter space.…
We demonstrate that the positive frequency modes for a complex scalar field in a constant electric field (Schwinger modes), in three different gauges, can be represented as exact Lorentzian worldline path integral amplitudes. Although the…
We compute quasinormal mode frequencies for static limits of physical black holes - semi-classical black hole solutions to Einstein-Hilbert gravity characterized by the finite formation time of an apparent horizon and its weak regularity.…
In a recent essay, we discussed the possibility of using polymer sizing to model the collapse of a single, long excited string to a black hole. In this letter, we apply this idea to bring further support to string/black hole correspondence.…
We study the quasinormal modes of a massive scalar field propagating on the Reissner-Nordstr\"om--de Sitter (RNdS) black hole black hole background on a 3+1-dimensional brane embedded in a higher-dimensional world. Using the WKB method…
Recent work on the quantum mechanics of near-extremal non-supersymmetric black holes has identified a characteristic $T^{3/2}$ scaling of the low temperature black hole partition function. This result has only been derived using the path…
We construct asymptotically flat, static spherically symmetric black holes with regular centre in $f(R,T)$ gravity coupled to nonlinear electrodynamics Lagrangian. We obtain generalized metric function of the Bardeen and Hayward black…
Recent works have suggested that nonlinear (quadratic) effects in black hole perturbation theory may be important for describing a black hole ringdown. We show that the technique of uniform approximations can be used to accurately compute…
Optimal extraction of information from gravitational-wave observations of binary black-hole coalescences requires detailed knowledge of the waveforms. Current approaches for representing waveform information are based on spin-weighted…