Related papers: Fuzzballs and Random Matrices
We investigate the (axial) quasinormal modes of black holes embedded in generic matter profiles. Our results reveal that the axial QNMs experience a redshift when the black hole is surrounded by various matter environments, proportional to…
From black hole perturbation theory, quasi-normal modes (QNMs) in spherically symmetric AdS black hole spacetimes are usually studied with the Horowitz and Hubeny methods [1] by imposing the Dirichlet or vanishing energy flux boundary…
These lecture notes discuss various aspects of the fuzzball paradigm, microstate geometries, and their role in gravitational phenomenology. We briefly introduce the information paradox and discuss how the fuzzball paradigm aims to resolve…
We study ramp and periodic dynamics of ultracold bosons in an one-dimensional (1D) optical lattice which supports quantum critical points separating a uniform and a $Z_3$ or $Z_4$ symmetry broken density-wave ground state. Our protocol…
Quantum Back Flow (QBF), discovered quite a few years back, is a generic purely quantum phenomenon, in which the probability of finding a particle in a direction is non-zero (and increasing for a certain period of time) even when the…
Phantom dark energy from DESI DR2 BAO [1]-[3] and bservations of Supermassive Black Hole (SMBH) at very high redshift present two new challenges in cosmology and astrophysics. In this work, we show that both problems can be addressed by…
We develop a number of novel "black-bounce" spacetimes. These are specific regular black holes where the "area radius" always remains non-zero, thereby leading to a "throat" that is either timelike (corresponding to a traversable wormhole),…
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 $\xi$…
Scalar perturbations during inflation can be substantially amplified by tiny features in the inflaton potential. A bump-like feature behaves like a local speed-breaker and lowers the speed of the scalar field, thereby locally enhancing the…
We provide an explicitly hermitian hamiltonian description for the spontaneous radiation of black holes, which is a many-level, multiple-degeneracy generalization of the usual Janeys-Cummings model for two-level atoms. By standard…
A spherically symmetric evolution model of self-gravitating matter with the equation of state P=wE (where w=const<-1) is considered. The equations of the model are written in the frame of reference comoving with matter. A criterion for the…
Dyson demonstrated an equivalence between infinite-range Coulomb gas models and classical random matrix ensembles for study of eigenvalue statistics. We introduce finite-range Coulomb gas (FRCG) models via a Brownian matrix process, and…
In this work, a new fast-roll (FR) mechanism to generate primordial black holes (PBHs) and gravitational waves (GWs) in generalized non-canonical natural inflation is introduced. In this model, choosing a suitable function for non-canonical…
Three postulates asserting the validity of conventional quantum theory, semi-classical general relativity and the statistical basis for thermodynamics are introduced as a foundation for the study of black hole evolution. We explain how…
At a surface between electromagnetic media the Maxwell equations allow either the usual boundary conditions, or exactly one alternative: continuity of E(perpendicular), H(perpendicular), D(parallel), B(parallel). These `flipped' conditions…
During the spin-down phase of the life of a higher-dimensional black hole, the emission of particles on the brane exhibits a strong angular variation with respect to the rotation axis of the black hole. It has been suggested that this…
The "swampland conjectures" have been recently suggested as a set of criteria to assess if effective field theories (EFTs) are consistent with a quantum gravity embedding. Such criteria, which restrict the behavior of scalar fields in the…
The ``fortuitous'' Bogomol'nyi-Prasad-Sommerfield (BPS) sector states in gauge theory have been argued to furnish a description, through holography, of generic BPS black hole microstates. They are expected to be strongly chaotic, a…
The horizon is a classical concept that arises in general relativity, and is therefore not clearly defined when the source cannot be reliably described by classical physics. To any (sufficiently) localised quantum mechanical wave-function,…
One version of the membrane paradigm states that as far as outside observers are concerned, black holes can be replaced by a dissipative membrane with simple physical properties located at the stretched horizon. We demonstrate that such a…