ﻻ يوجد ملخص باللغة العربية
We present a Maple11+GRTensorII based symbolic calculator for instanton metrics using Newman-Penrose formalism. Gravitational instantons are exact solutions of Einsteins vacuum field equations with Euclidean signature. The Newman-Penrose formalism, which supplies a toolbox for studying the exact solutions of Einsteins field equations, was adopted to the instanton case and our code translates it for the computational use.
Since its introduction in 1962, the Newman-Penrose formalism has been widely used in analytical and numerical studies of Einsteins equations, like for example for the Teukolsky master equation, or as a powerful wave extraction tool in numerical relat
A universal geometric inequality for bodies relating energy, size, angular momentum, and charge is naturally implied by Bekensteins entropy bounds. We establi
We provide a detailed proof of Hawkings singularity theorem in the regularity class $C^{1,1}$, i.e., for spacetime metrics possessing locally Lipschitz continuous first derivatives. The proof uses recent results in $C^{1,1}$-causality theory and is b
We reexamine the relation between the Aretakis charge of an extremal black hole spacetime and the Newman-Penrose charge of a weakly asymptotically flat spacetime obtained from the original one through radial inversion and conformal mapping. Building
In this work we present a simple, approximate method for analysis of the basic dynamical and thermodynamical characteristics of Kerr-Newman black hole. Instead of the complete dynamics of the black hole self-interaction we consider only such stable (