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We develop an approach to the theory of relativistic geometric flows and emergent gravity defined by entropy functionals and related statistical thermodynamics models. Nonholonomic deformations of G. Perelman's functionals and related…

General Physics · Physics 2021-01-29 Sergiu I. Vacaru , Elşen Veli Veliev , Laurenţiu Bubuianu

The field equations in modified gravity theories possess an important decoupling property with respect to certain classes of nonholonomic frames. This allows us to construct generic off--diagonal solutions depending on all spacetime…

General Relativity and Quantum Cosmology · Physics 2015-02-23 Sergiu I. Vacaru

We argue that the Einstein gravity theory can be reformulated in almost Kahler (nonsymmetric) variables with effective symplectic form and compatible linear connection uniquely defined by a (pseudo) Riemannian metric. A class of…

General Relativity and Quantum Cosmology · Physics 2009-07-24 Sergiu I. Vacaru

This paper presents solutions to Einstein's equation -- and the numerical methods used to construct them -- that describe simple cosmological models on manifolds with compact non-orientable spatial slices. These solutions have been…

General Relativity and Quantum Cosmology · Physics 2026-04-28 Fan Zhang , Lee Lindblom

The field equations for Einstein-Maxwell-dilaton gravity in $D$ dimensions are reduced to an effective one-dimensional system under the influence of exponential potentials. Various cases where exact solutions can be found are explored. With…

General Relativity and Quantum Cosmology · Physics 2017-05-10 Yen-Kheng Lim

We investigate Lie symmetries of Einstein's vacuum equations in N dimensions, with a cosmological term. For this purpose, we first write down the second prolongation of the symmetry generating vector fields, and compute its action on…

General Relativity and Quantum Cosmology · Physics 2015-05-26 Louis Marchildon

This thesis studies modified theories of gravity from a geometric viewpoint. We review the motivations for considering alternatives to General Relativity and cover the mathematical foundations of gravitational theories in Riemannian and…

General Relativity and Quantum Cosmology · Physics 2024-01-24 Erik Jensko

Einstein gravity at $D\rightarrow 2$ limit can be obtained from the Kaluza-Klein procedure by taking the dimensions of the internal space to zero while keeping only the breathing mode. The resulting scalar-tensor theory can be further…

High Energy Physics - Theory · Physics 2023-03-29 Qi-Yuan Mao , H. Lu

In this work we present an approximate solution of the Einstein equations describing a global model for the gravitational field generated by a bounded, self-gravitating stationary and axisymmetric body rotating rigidly with constant angular…

General Relativity and Quantum Cosmology · Physics 2007-05-23 J. Martin-Martin , A. Molina , E. Ruiz

We study the homogeneous but anisotropic Bianchi type-V cosmological model with time-dependent gravitational and cosmological "constants". Exact solutions of the Einstein field equations (EFEs) are presented in terms of adjustable…

General Relativity and Quantum Cosmology · Physics 2018-07-30 Alnadhief H. A. Alfedeel , Amare Abebe , Hussam M. Gubara

We construct asymptotically Euclidean solutions of the vacuum Einstein constraint equations with an apparent horizon boundary condition. Specifically, we give sufficient conditions for the constant mean curvature conformal method to…

General Relativity and Quantum Cosmology · Physics 2015-06-25 David Maxwell

We develop the method of anholonomic frames with associated nonlinear connection (in brief, N--connection) structure and show explicitly how geometries with local anisotropy (various type of Finsler--Lagrange--Cartan--Hamilton geometry) can…

High Energy Physics - Theory · Physics 2007-05-23 Sergiu I. Vacaru

Einstein's theory of general relativity models the physical universe using spacetimes which satisfy Einstein's gravitational field equations. To date, Einstein's theory has been enormously successful in modeling observed gravitational…

General Relativity and Quantum Cosmology · Physics 2016-10-21 James Isenberg

The generalized harmonic representation of Einstein's equation is manifestly hyperbolic for a large class of gauge conditions. Unfortunately most of the useful gauges developed over the past several decades by the numerical relativity…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Lee Lindblom , Keith D. Matthews , Oliver Rinne , Mark A. Scheel

We consider the curvatures 2 form asociated with AdSL4 valued one-form gauge connetion, and then we construct a four-dimensional action that generalize the Einstein-Hilbert gravity. It is shown that the Maxwell extension of Einstein gravity…

High Energy Physics - Theory · Physics 2022-09-07 L. Cardenas , J. Diaz , P. Salgado , D. Salgado

Towards the investigation of the full dynamics in higher-dimensional and/or stringy gravitational model, we present the basic equations of the Einstein-Gauss-Bonnet gravity theory. We show $(N+1)$-dimensional version of the ADM…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Takashi Torii , Hisa-aki Shinkai

We discuss the initial value problem for the Einstein equations in Hitchin's generalised geometry for the case of closed divergence (which correspond to the equations of motion in the bosonic part of the NS-NS sector in type II…

Differential Geometry · Mathematics 2026-01-09 Oskar Schiller

Some exact static solutions for Einstein gravity in 2+1 dimensions coupled to abelian gauge field are discussed. Some of these solutions are three-dimensional analogs of the Schwarzschild black holes. The metrics in the regions inside and…

High Energy Physics - Theory · Physics 2009-10-22 Ian I. Kogan

After a brief summary of the foundations of general relativity, we will concentrate on the stationary exact solutions of the Einstein and Einstein-Maxwell equations. A number of these solutions can be interpreted as black holes,…

General Relativity and Quantum Cosmology · Physics 2011-09-06 Gérard Clément

We show that the Schwarzschild solution can be embedded in a class of nonstandard solutions of the vacuum Einstein's equations with arbitrary rotation curves. These nonstandard solutions have to be taken as physical if dark matter as needed…

General Relativity and Quantum Cosmology · Physics 2015-04-28 Günter Scharf