Related papers: Fermion perturbations in string-theory black holes
We study fermionic perturbations in the background of a two and five-dimensional dilatonic black holes. Then, we compute the reflection and transmission coefficients and the absorption cross section for fermionic fields, and we show…
Deep conceptual problems associated with classical black holes can be addressed in string theory by the ``fuzzball'' paradigm, which provides a microscopic description of a black hole in terms of a thermodynamically large number of regular,…
We compute the spectrum of quasinormal frequencies of regular black holes obtained in the presence of Non-Linear Electrodynamics. In particular, we perturb the black hole with a minimally coupled massive scalar field, and we study the…
The classical black hole background of two-dimensional string theory is examined after including the effect of the tachyon field. Keeping all terms upto $O(T^2)$, and making no other approximations, the only consistent classical solution to…
New string dynamics is formulated on the basis of the extended set of supergauge constraints including not only supergauge Virasoro conditions but also nilpotent supercurrent constraints . This approach arises from a natural generalization…
In this paper we are studying the scattering of massless Dirac fermions by Schwarzschild and Reissner-Nordstr\"om black holes. This is done by applying the partial wave analysis to the scattering modes obtained after solving the massless…
Recent progress on string theory in curved spacetimes is reviewed. The string dynamics in cosmological and black hole spacetimes is investigated.The methods to solve the string equations of motion in curved spacetimes are described.That is,…
In this work, we investigate massive charged scalar perturbations in the background of three-dimensional dilaton black holes with a cosmological constant. We demonstrate that the wave equations governing the dynamics of these perturbations…
By finding the spinor eigenvalues for a single deficit angle (d-2)-sphere, we derive the radial potential for fermions on a d-dimensional black hole background that is embedded on a codimension two brane with conical singularity, where the…
We present solutions of the low-energy four-dimensional heterotic string corresponding to $p$-branes with $p=0,1,2$, which are characterized by a mass per unit $p$-volume, ${\cal M}_{p+1}$, and topological ``magnetic'' charge, $g_{p+1}$. In…
In this study, we analytically examine the behavior of a fermion-antifermion pair near the horizon of a static BTZ black hole using a fully covariant two-body Dirac equation with a position-dependent mass. This formulation leads to a set of…
We study brane-world models with variable brane tension and compute corrections to the horizon of a black string along the extra dimension. The four-dimensional geometry of the black string on the brane is obtained by means of the minimal…
In this paper, we investigated the Dirac and Klein-Gordan equations, as well as the greybody factor for a Schwarzschild black hole (SBH) immersed in quintessence and associated with a cloud of strings. Primarily, we study the Dirac equation…
Baryon number violation is discussed in gauge unified orbifold models of type II string theory with intersecting Dirichlet branes. We consider setups of D6-branes which extend along the flat Minkowski space-time directions and wrap around…
The matrix model formulation of two dimensional string theory has been shown to admit time dependent classical solutions whose closed string duals are geodesically incomplete space-times with space-like boundaries. We investigate some…
We consider perturbations of the massless Dirac field in the background of a black hole solution found by Bodendorfer, Mele, and M\"{u}nch (BMM), using a polymerization technique that furnishes contributions inspired by Loop Quantum Gravity…
So far the study of black hole perturbations has been mostly focussed upon the classical black holes with singularities at the origin and hidden by event horizon. Compared to that, the regular black holes are a completely new class of…
Extremal N=2 black holes in four dimensions can be described by an ensemble of D3-branes wrapped on internal supersymmetric three-cycles of Calabi-Yau threefolds on which type IIB superstring theory is compactified. We construct a similar…
We develop the perturbation theory for R^2 string-corrected black hole solutions in d dimensions. After having obtained the master equation and the alpha'-corrected potential under tensorial perturbations of the metric, we study the…
We study the stability under scalar perturbations, and we compute the quasinormal modes of the Einstein-Born-Infeld dilaton spacetime in 1+3 dimensions. Solving the full radial equation in terms of hypergeometric functions, we provide an…