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Related papers: Note on a class of anisotropic Einstein metrics

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An $(\alpha,\beta)$-metric is defined by a Riemannian metric $\alpha$ and $1$-form $\beta$. In this paper, we study a known class of two-dimensional $(\alpha,\beta)$-metrics of vanishing S-curvature. We determine the local structure of…

Differential Geometry · Mathematics 2014-06-12 Guojun Yang

We develop new algorithms for approximating extremal toric K\"ahler metrics. We focus on an extremal metric on $\mathbb{CP}^{2}\sharp2\overline{\mathbb{CP}}^{2}$, which is conformal to an Einstein metric (the Chen-LeBrun-Weber metric). We…

Differential Geometry · Mathematics 2016-01-12 Stuart James Hall , Thomas Murphy

The main objective of this work, is to show two inequivalent methods to obtain new spherical symmetric solutions of Einstein's Equations with anisotropy in the pressures in isotropic coordinates. This was done inspired by the MGD method,…

General Relativity and Quantum Cosmology · Physics 2020-01-08 C. Las Heras , P. León

Analytic gravitational collapse and expansion solutions with anisotropic pressure are generated. Metric functions are found by requiring zero heat flow scalar. It emerges that a single function generates the anisotropic solutions. Each…

General Relativity and Quantum Cosmology · Physics 2013-09-30 E. N. Glass

In this work, we present a class of relativistic and well-behaved solution to Einstein's field equations for anisotropic matter distribution. We perform our analysis by using the Buchdahl ansatz for the metric function grr. Three different…

General Relativity and Quantum Cosmology · Physics 2022-03-29 Amit Kumar Prasad , Jitendra Kumar

We consider the Einstein deformations of the reducible rank two symmetric spaces of noncompact type. If $M$ is the product of any two real, complex, quaternionic or octonionic hyperbolic spaces, we prove that the family of nearby Einstein…

Differential Geometry · Mathematics 2007-05-23 Olivier Biquard , Rafe Mazzeo

Starting with a generalized theory of 2+1 gravity containing an Immirzi like parameter, we derive the modified laws of black hole mechanics using the formalism of weak isolated horizons. Definitions of horizon mass and angular momentum…

General Relativity and Quantum Cosmology · Physics 2011-11-01 Rudranil Basu , Ayan Chatterjee

Motivated by recent claims stating that the acceleration of the present Universe is due to fluctuations with wavelength larger than the Hubble radius, we present a general analysis of various perturbative solutions of fully inhomogeneous…

Astrophysics · Physics 2009-11-13 Massimo Giovannini

To study asymptotic structures, we regularize Einstein's field equations by means of conformal transformations. The conformal factor is chosen so that it carries a dimensional scale that captures crucial asymptotic features. By choosing a…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Niklas Rohr , Claes Uggla

In this work, an exact solution of Einstein's field equations in isotropic coordinates for anisotropic matter distribution is obtained by considering a particular metric choice of metric potential $g_{rr}$. To check the feasibility of the…

General Relativity and Quantum Cosmology · Physics 2022-06-29 B. S. Ratanpal , Bhavesh Suthar

In this note we prove that a special family of Killing potentials on certain Hirzebruch complex surfaces, found by Futaki and Ono, gives rise to new conformally K\"ahler, Einstein-Maxwell metrics. The correspondent K\"ahler metrics are…

Differential Geometry · Mathematics 2021-01-08 Isaque Viza de Souza

A pair of anisotropic exceptional points (EPs) of arbitrary order are found in a class of non-Hermitian random systems with asymmetric hoppings. Both eigenvalues and eigenvectors exhibit distinct behaviors when these anisotropic EPs are…

Mesoscale and Nanoscale Physics · Physics 2019-06-12 Yi-Xin Xiao , Zhao-Qing Zhang , Zhi Hong Hang , C. T. Chan

Static spherically symmetric anisotropic source has been studied for the Einstein-Maxwell field equations assuming the erstwhile cosmological constant $ \Lambda $ to be a space-variable scalar, viz., $ \Lambda = \Lambda(r) $. Two cases have…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Saibal Ray , Sumana Bhadra , Anand S. Sengupta

We prove the existence of Sasakian-Einstein metrics on infinitely many rational homology spheres in all odd dimensions greater than 3. In dimension 5 we obain somewhat sharper results. There are examples where the number of effective…

Differential Geometry · Mathematics 2008-11-26 Charles P. Boyer , Krzysztof Galicki

We study a spherically symmetric spacetime made of anisotropic fluid of which radial equation of state is given by $p_1 = -\rho$. This provides analytic solutions and a good opportunity to study the static configuration of black hole plus…

General Relativity and Quantum Cosmology · Physics 2018-12-27 Inyong Cho , Hyeong-Chan Kim

In the weak field regime, gravitational waves can be considered as being made up of collisionless, relativistic tensor modes that travel along null geodesics of the perturbed background metric. We work in this geometric optics picture to…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-17 Carlo R. Contaldi

The cosmological principle is a cornerstone of the standard cosmological model. However, recent observations suggest potential deviations from this assumption, hinting at a small anisotropic expansion. Such an expansion can arise from…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-23 Jose L. Palacios-Córdoba , J. Bayron Orjuela-Quintana , Gabriela A. Valencia-Zuñiga , César A. Valenzuela-Toledo

We analyse the mathematical underpinnings of a mixed hyperbolic-elliptic form of the Einstein equations of motion in which the lapse function is determined by specified mean curvature and the shift is arbitrary. We also examine a new…

General Relativity and Quantum Cosmology · Physics 2012-08-27 Y. Choquet-Bruhat , J. W. York,

The Hartle-Thorne metric is an exact solution of vacuum Einstein field equations that describes the exterior of any slowly and rigidly rotating, stationary and axially symmetric body. The metric is given with accuracy up to the second order…

General Relativity and Quantum Cosmology · Physics 2007-05-23 M. A. Abramowicz , G. J. E. Almergren , W. Kluzniak , A. V. Thampan

It is well known that the viscous Bianchi type-I metric of the Kasner form is not able to describe an anisotropic universe, which satisfies the second law of thermodynamics and the dominant energy condition in Einstein's theory of gravity.…

General Relativity and Quantum Cosmology · Physics 2008-11-12 Seokcheon Lee
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