Searcharxiv⌕ Search

arXiv subjects

N. Breton

Publications and source records attributed to N. Breton.

2 recordsLinked to original sources
arXiv2022

Energy extraction in electrostatic extreme binary black holes

Relying on the Penrose process mechanism, we study the possibility of energy extraction from a binary system composed of two extreme electrostatic black holes (BHs) oppositely charged, separated by a strut described by Bonnor's metric (BM). We determined and plotted the generalized ergosphere that surrounds only one of the BH. We demonstrate the existence of non closed orbits of negative energy outside the event horizon; these orbits allow the possibility of energy extraction by particle disintegration from a system described by the BM. Besides we prove that the extraction process can occur when a charged test particle and the BH have opposite charges; also, we analyzed the efficiency of the process.

gr-qc↗
arXiv2016

Quasinormal modes of nonlinear electromagnetic black holes from unstable null geodesics

The expressions for the quasinormal modes (QNMs) of black holes with nonlinear electrodynamics, calculated in the eikonal approximation, are presented. In the eikonal limit QNMs of black holes are determined by the parameters of the circular null geodesics. The unstable circular null orbits are derived from the effective metric that is the one obeyed by light rays under the influence of a nonlinear electromagnetic field. As an illustration we calculate the QNMs of four nonlinear electromagnetic black holes, two singular and two regular, namely from Euler-Heisenberg and Born-Infeld theories, for singular, and the magnetic Bardeen black hole and the one derived by Bronnikov for regular ones. Comparison is shown with the QNMs of the linear electromagnetic counterpart, their Reissner-Nordström black hole.

gr-qc↗