English
Related papers

Related papers: Local and Approximate classification of spacetimes…

200 papers

In this paper we derive a general solution for the most general rotating and twisting locally rotationally symmetric spacetimes. This is achieved in three steps. First we decompose the manifold via 1+1+2 semi-tetrad formalism that yields a…

General Relativity and Quantum Cosmology · Physics 2017-10-04 Sayuri Singh , George F. R. Ellis , Rituparno Goswami , Sunil D. Maharaj

A mesh-free numerical method for solving linear elliptic PDE's using the local kernel theory that was developed for manifold learning is proposed. In particular, this novel approach exploits the local kernel theory which allows one to…

Numerical Analysis · Mathematics 2019-07-02 Faheem Gilani , John Harlim

We embed the Penrose limit into the Weyl classical double copy. Thereby, we provide a lift of the double copy properties of plane wave spacetimes into black hole geometries and we open a novel avenue towards taking the classical double copy…

High Energy Physics - Theory · Physics 2024-07-12 Samarth Chawla , Kwinten Fransen , Cynthia Keeler

We apply a covariant and generic procedure to obtain explicit expressions of the transverse frames that a type I spacetime admits in terms of an arbitrary initial frame. We also present a simple and general algorithm to obtain the Weyl…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Joan Josep Ferrando , Juan Antonio Sáez

Using extensions of the Newman-Penrose and Geroch-Held-Penrose formalisms to five dimensions, we invariantly classify all Petrov type $D$ vacuum solutions for which the Riemann tensor is isotropic in a plane orthogonal to a pair of Weyl…

General Relativity and Quantum Cosmology · Physics 2011-09-28 Alfonso García-Parrado Gómez-Lobo , Lode Wylleman

We use localization to evaluate the functional integral of string field theory on AdS_2xS^2 background corresponding to the near horizon geometry of supersymmetric black holes in 4d compactifications with N=2 supersymmetry. In particular,…

High Energy Physics - Theory · Physics 2013-05-13 Atish Dabholkar , Joao Gomes , Sameer Murthy

It is shown that the generally covariant Duffin-Kemmer-Petiau equation, formulated in the frame of the Tetrode-Weyl-Fock-Ivanenko tetrad formalism, allows for a non-relativistic approximation if the metric tensor is of a special form. The…

High Energy Physics - Theory · Physics 2011-09-15 A. A. Bogush , V. V. Kisel , N. G. Tokarevskaya , V. M. Red'kov

An approximate solution to Einstein's equations representing two widely-separated non-rotating black holes in a circular orbit is constructed by matching a post-Newtonian metric to two perturbed Schwarzschild metrics. The spacetime metric…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Kashif Alvi

A solution to the equivalence problem in three-dimensional gravity is given and a practically useful method to obtain a coordinate invariant description of local geometry is presented. The method is a nontrivial adaptation of Karlhede…

General Relativity and Quantum Cosmology · Physics 2011-03-28 F. C. Sousa , J. B. Fonseca , C. Romero

We consider and analyze applying a spectral inverse iteration algorithm and its subspace iteration variant for computing eigenpairs of an elliptic operator with random coefficients. With these iterative algorithms the solution is sought…

Numerical Analysis · Computer Science 2017-06-16 Harri Hakula , Mikael Laaksonen

A bilinear estimate in terms of Bourgain spaces associated with a linearised Kadomtsev-Petviashvili-type equation on the three-dimensional torus is shown. As a consequence, time localized linear and bilinear space time estimates for this…

Analysis of PDEs · Mathematics 2009-01-14 Axel Grünrock

This article is the second one of three successive articles of the authors on the matrix-weighted Besov-type and Triebel--Lizorkin-type spaces. In this article, we obtain the sharp boundedness of almost diagonal operators on matrix-weighted…

Functional Analysis · Mathematics 2024-08-22 Fan Bu , Tuomas Hytönen , Dachun Yang , Wen Yuan

In this study, we develop a modeling framework based on spatio-temporal generalized random fields to simulate the time-evolving accretion flows and their associated imaging signatures around rotating regular black holes. We extend the…

High Energy Astrophysical Phenomena · Physics 2025-07-30 Sen Guo , En-Wei Liang , Yu-Xiang Huang , Yu Liang , Qing-Quan Jiang , Kai Lin , Li-Fang Li

We present a novel family of slowly rotating black hole solutions in four, and higher dimensions, that extend the well known Lense-Thirring spacetime and solve the field equations to linear order in rotation parameter. As "exact metrics" in…

General Relativity and Quantum Cosmology · Physics 2022-03-23 Finnian Gray , David Kubiznak

Approximation of non-linear kernels using random feature maps has become a powerful technique for scaling kernel methods to large datasets. We propose $\textit{Tensor Sketch}$, an efficient random feature map for approximating polynomial…

Data Structures and Algorithms · Computer Science 2025-05-20 Ninh Pham , Rasmus Pagh

Highly localized kernels constructed by orthogonal polynomials have been fundamental in recent development of approximation and computational analysis on the unit sphere, unit ball and several other regular domains. In this work we first…

Classical Analysis and ODEs · Mathematics 2021-09-09 Yuan Xu

This paper analyzes the approximation properties of spaces of piece-wise tensor product polynomials over box meshes with a focus on application to IsoGeometric Analysis (IGA). The errors are measured in Lebesgue norms. Estimates of…

Numerical Analysis · Mathematics 2018-12-21 Andrea Bressan , Tom Lyche

Two tetrad spaces reproducing spherically symmetric spacetime are applied to the equations of motion of higher-order torsion theories. Assuming the existence of conformal Killing vector, two isotropic solutions are derived. We show that the…

General Physics · Physics 2016-02-24 Gamal G. L. Nashed

Improved semiclassical techniques are developed and applied to a treatment of a real scalar field in a $D$-dimensional gravitational background. This analysis, leading to a derivation of the thermodynamics of black holes, is based on the…

High Energy Physics - Theory · Physics 2007-05-23 Horacio E. Camblong , Carlos R. Ordonez

We derive an expression for functional determinants in thermal spacetimes as a product over the corresponding quasinormal modes. As simple applications we give efficient computations of scalar determinants in thermal AdS, BTZ black hole and…

High Energy Physics - Theory · Physics 2010-05-21 Frederik Denef , Sean A. Hartnoll , Subir Sachdev