arXiv subjects

C. Sahabandu

Publications and source records attributed to C. Sahabandu.

4 recordsLinked to original sources

arXiv2005

Thermodynamics of static black objects in D dimensional Einstein-Gauss-Bonnet gravity with D-4 compact dimensions

We investigate the thermodynamics of static black objects such as black holes, black strings and their generalizations to D dimensions (`black branes') in a gravitational theory containing the four dimensional Gauss-Bonnet term in the action, when D-4 of the dimensions are compactified on a torus. The entropies of black holes and black branes are compared to obtain information on the stability of these objects and to find their phase diagrams. We demonstrate the existence of a critical mass, which depends on the scale of the compactified dimensions, below which the black hole entropy dominates over the entropy of the black membrane.

gr-qc↗

arXiv2004

Analytic approximation to 5 dimensional Black Holes with one compact dimension

We study black hole solutions in $R^4\times S^1$ space, using an expansion to fourth order in the ratio of the radius of the horizon, $μ$, and the circumference of the compact dimension, $L$. A study of geometric and thermodynamic properties indicates that the black hole fills the space in the compact dimension at $ε(μ/L)^2\simeq0.1$. At the same value of $ε$ the entropies of the uniform black string and of the black hole are approximately equal.

hep-th↗

arXiv2004

Small Black Holes on Branes: Is the horizon regular or singular ?

We investigate the following question: Consider a small mass, with $ε$ (the ratio of the Schwarzschild radius and the bulk curvature length) much smaller than 1, that is confined to the TeV brane in the Randall-Sundrum I scenario. Does it form a black hole with a regular horizon, or a naked singularity? The metric is expanded in $ε$ and the asymptotic form of the metric is given by the weak field approximation (linear in the mass). In first order of $ε$ we show that the iteration of the weak field solution, which includes only integer powers of the mass, leads to a solution that has a singular horizon. We find a solution with a regular horizon but its asymptotic expansion in the mass also contains half integer powers.

gr-qc↗

arXiv2004

Small Black Holes in Randall-Sundrum type I Scenario

An approximation method to study the properties of a small black hole located on the TeV brane in the Randall-Sundrum type I scenario is presented. The method enables us to find the form of the metric close to the matter distribution when its asymptotic form is given. The short range solution is found as an expansion in the ratio between the Schwarzschild radius of the black hole and the curvature length of the bulk. Long range properties are introduced using the linearized gravity solution as an asymptotic boundary condition. The solution is found up to first order. It is valid in the region close to the horizon but is not valid on the horizon. The regularity of the horizon is still under study.

gr-qc↗