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Related papers: Note on a class of anisotropic Einstein metrics

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The detection of a time variation of the angle between two distant sources would reveal an anisotropic expansion of the Universe. We study this effect of "cosmic parallax" within the "ellipsoidal universe" model, namely a particular…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-29 L. Campanelli , P. Cea , G. L. Fogli , L. Tedesco

This article provides an attempt to extend concepts from the theory of Riemannian manifolds to piecewise linear spaces. In particular we propose an analogue of the Ricci tensor, which we give the name of an Einstein vector field. On a given…

Mathematical Physics · Physics 2016-05-04 Robert Schrader

Lorentz proposed a classical model of electron in which electron was assumed to have only 'electromagnetic mass'. We modeled electron as charged anisotropic perfect fluid sphere admitting non static conformal symmetry. It is noticed that…

High Energy Physics - Theory · Physics 2011-10-11 I. Radinschi , F. Rahaman , M. Kalam , K. Chakraborty

On a smooth metric measure spacetime $(M,g,e^{-f} dvol_g)$, we define a weighted Einstein tensor. It is given in terms of the Bakry-\'Emery Ricci tensor as a tensor which is symmetric, divergence-free, concomitant of the metric and the…

Differential Geometry · Mathematics 2022-06-29 Miguel Brozos-Vázquez , Diego Mojón-Álvarez

We study spherically symmetric spacetimes for matter distributions with isotropic pressures. We generate new exact solutions to the Einstein field equations which also contains isotropic pressures. We develop an algorithm that produces a…

General Relativity and Quantum Cosmology · Physics 2014-12-23 S. Ngubelanga , S. D. Maharaj

A new class of solutions describing analytical solutions for compact stellar structures has been developed within the tenets of General Relativity. Considering the inherent anisotropy in compact stars, a stable and causal model for…

General Relativity and Quantum Cosmology · Physics 2021-10-14 Jay Solanki , Bhashin Thakore

Deflection of light due to massive objects was predicted by Einstein in his General Theory of Relativity. This deflection of light has been calculated by many researchers in past, for spherically symmetric objects. But, in reality, most of…

General Relativity and Quantum Cosmology · Physics 2023-03-07 Ranchhaigiri Brahma , A. K. Sen

We present the analytic forms for the spectra of the cosmological perturbations from an initially anisotropic universe for the high momentum modes in the context of WKB approximations, as the continuation of the work [29]. We consider the…

General Relativity and Quantum Cosmology · Physics 2011-03-28 Hyeong-Chan Kim , Masato Minamitsuji

Azimuthal anisotropy of final particle distributions was originally introduced as a signature of transverse collective flow. We show that finite anisotropy in momentum space can result solely from the shape of the particle emitting source.…

Nuclear Theory · Physics 2009-10-09 P. Huovinen , P. F. Kolb , U. Heinz

In this paper, we study a new class of Finsler metrics, F=\alpha\phi(b^2,s), s:=\beta/\alpha, defined by a Riemannian metric \alpha and 1-form \beta. It is called general (\alpha, \beta) metric. In this paper, we assume \phi be coefficient…

Differential Geometry · Mathematics 2017-06-28 A. Ala , A. Behzadi , M. Rafiei-Rad

We present new analytical distribution functions for anisotropic spherical galaxies. They have the density profiles of the gamma-models, which allow a wide range of central density slopes, and are widely used to fit elliptical galaxies and…

Astrophysics · Physics 2008-11-26 Pieter Buyle , Chris Hunter , Herwig Dejonghe

We study anisotropic geometric energy functionals defined on a class of k-dimensional surfaces in a Euclidean space. The classical notion of ellipticity, coming from Almgren, for such functionals is investigated. We prove a variant of a…

Analysis of PDEs · Mathematics 2025-07-21 Maciej Lesniak

From a particularly simple solution of the Ernst equation, we build a solution of the vacuum stationary axisymmetric Einstein equations depending on three parameters. The parameters are associated to the total mass of the source and its…

General Relativity and Quantum Cosmology · Physics 2008-11-26 J. Gariel , G. Marcilhacy , N. O. Santos

We study solutions of Einstein equations with negative cosmological constant in five dimensions that describe black holes whose event horizons are homogeneous, anisotropic spaces. We focus on the case where the constant-time slices of the…

High Energy Physics - Theory · Physics 2024-04-30 Jose Figueroa , Gaston Giribet , Anibal Neira-Gallegos , Julio Oliva , Marcelo Oyarzo

In this paper, we prove sharp estimates and existence results for anisotropic nonlinear elliptic problems with lower order terms depending on the gradient. Our prototype is: $ \left\{ \begin{array}{ll} -\mathcal Q_{p}u =[H(Du)]^{q}+f(x)…

Analysis of PDEs · Mathematics 2014-02-14 Francesco Della Pietra , Nunzia Gavitone

In a recent article the first three authors proved that in dimension $4m+1$ all homotopy spheres that bound parallelizable manifolds admit Einstein metrics of positive scalar curvature which, in fact, are Sasakian-Einstein. They also…

Differential Geometry · Mathematics 2007-05-23 Charles P. Boyer , Krzysztof Galicki , János Kollár , Evan Thomas

We propose an effective anisotropic fluid description for a generic infrared-modified theory of gravity. In our framework, the additional component of the acceleration, commonly attributed to dark matter, is explained as a radial pressure…

General Relativity and Quantum Cosmology · Physics 2017-12-06 Mariano Cadoni , Roberto Casadio , Andrea Giusti , Wolfgang Mück , Matteo Tuveri

We demonstrate a technique to generate new class of exact solutions to the Einstein-Maxwell system describing a static spherically symmetric relativistic star with anisotropic matter distribution. An interesting feature of the new class of…

General Physics · Physics 2020-11-25 K. Komathiraj , Ranjan Sharma

We present model for anisotropic compact star under the general theory of relativity of Einstein. In the study a 4-dimensional spacetime has been considered which is embedded into the 5-dimensional flat metric so that the spherically…

General Physics · Physics 2018-08-01 S. K. Maurya , Saibal Ray , Shounak Ghosh , Sarbajit Manna , Smitha T. T

We obtain a class of anisotropic spherically symmetric relativistic solutions of compact objects in hydrostatic equilibrium in the $f(R,T) =R+2\chi T$ modified gravity, where $R$ is the Ricci scalar, $T$ is the trace of the energy momentum…

General Physics · Physics 2020-09-18 S. Dey , A. Chanda , B. C. Paul