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Related papers: Einstein gravity of a diffusing fluid

200 papers

Unimodular gravity is an alternative theory of gravity to general relativity. The gravitational field equations are given by the trace-free version of Einstein's field equations. Due to the structure of the theory, unimodular gravity admits…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-18 M. P. Piccirilli , G. León

In this essay we marshal evidence suggesting that Einstein gravity may be an emergent phenomenon, one that is not ``fundamental'' but rather is an almost automatic low-energy long-distance consequence of a wide class of theories.…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Carlos Barcelo , Matt Visser , Stefano Liberati

We investigate the global dynamics of the field equations of (pure) quadratic theories of gravity which generalise Einstein's theory in spatially flat homogeneous and isotropic cosmological models with a perfect fluid. We introduce global…

General Relativity and Quantum Cosmology · Physics 2026-03-11 Artur Alho , Margarida Lima , Filipe C. Mena

We study self-consistent static solutions for an Einstein universe in a graph-based induced gravity. The one-loop quantum action is computed at finite temperature. In particular, we demonstrate specific results for the models based on cycle…

General Relativity and Quantum Cosmology · Physics 2009-08-11 Nahomi Kan , Kiyoshi Shiraishi

The two defining features of the Einsteinian gravity are that it is self interactive as well as it links universally to all particles including zero mass particles. In the process of obtaining the Schwarzshild solution for gravitational…

General Relativity and Quantum Cosmology · Physics 2015-08-06 Naresh Dadhich

I describe the Einstein's gravitation of 3+1 dimensional spacetimes using the (2,2) formalism without assuming isometries. In this formalism, quasi-local energy, linear momentum, and angular momentum are identified from the four Einstein's…

General Relativity and Quantum Cosmology · Physics 2024-06-03 Jong Hyuk Yoon

The present work deals with a cosmological model having particle creation mechanism in the framework of irreversible thermodynamics. In the second order non-equilibrium thermodynamical prescription, the particle creation rate is treated as…

General Relativity and Quantum Cosmology · Physics 2015-05-01 Subenoy Chakraborty , Supriya Pan , Subhajit Saha

A quantum kinetic equation is obtained for an inhomogeneous solid having arbitrary gradient concentration and chemical potential. We find, starting from nonequilibrium statistical operator, a new equation to describe atom migration in solid…

Statistical Mechanics · Physics 2017-03-31 Y. Bilotsky , M. Gasik , B. Lev

We investigate theories in which gravity arises as a consequence of entropy. We distinguish between two approaches to this idea: holographic gravity, in which Einstein's equation arises from keeping entropy stationary in equilibrium under…

High Energy Physics - Theory · Physics 2016-06-23 Sean M. Carroll , Grant N. Remmen

The existence and stability of the Einstein static solution have been built in the Einstein-Cartan gravity. We show that this solution in the presence of perfect fluid with spin density satisfying the Weyssenhoff restriction is cyclically…

General Relativity and Quantum Cosmology · Physics 2014-06-11 K. Atazadeh

The black hole area theorem suggests that classical general relativity is the thermodynamic limit of a quantum statistics. The degrees of freedom of the statistical theory cannot be the spacetime metric. We argue that the statistical theory…

General Relativity and Quantum Cosmology · Physics 2009-05-18 T. P. Singh

Careful analysis of parametrized variational principles in mechanics and field theory leads to a generalization of Einstein theory that includes a cosmological stress tensor. This generalization also follows by restricting variations of the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Arlen Anderson

In 1919 Einstein tried to solve the problem of the structure of matter by assuming that the elementary particles are held together solely by gravitational forces. In addition, Einstein also assumed the presence inside matter of…

General Relativity and Quantum Cosmology · Physics 2021-04-19 Zahra Haghani , Tiberiu Harko , Shahab Shahidi

Extensions of Einstein gravity which allow the gravitational constant $G$ to change with time as the universe evolves may provide a resolution to the horizon problem without invoking a period of vacuum domination and without the subsequent…

Astrophysics · Physics 2009-10-22 Janna J Levin , Katherine Freese

By following the general guiding principle that nothing should be prescribed or imposed on the universal entity, spacetime, we establish that it is the homogeneity (by which we mean homogeneity and isotropy of space and homogeneity of time)…

General Relativity and Quantum Cosmology · Physics 2015-05-28 Naresh Dadhich

This paper has been withdrawn by the author after further work showed the proposed theoretical approach cannot fit planetary perihelion precession data. As presented, the theory doesn't fit gravitational light deflection by the sun either,…

General Physics · Physics 2014-03-28 Steven Kenneth Kauffmann

The Einstein equations for an inhomogeneous irrotational dust universe are analysed. A set of mild assumptions, all of which are shared by the standard FLRW type scenarios, results in a model that depends only on the distribution of scalar…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-19 Harald Skarke

The Einstein equations of general relativity reduce, when the spacetime metric is of the Friedmann--Lemaitre--Robertson--Walker type governing an isotropic and homogeneous universe, to the Friedmann equations, which is a set of nonlinear…

General Relativity and Quantum Cosmology · Physics 2024-07-30 Yisong Yang

An overlap between the general relativist and particle physicist views of Einstein gravity is uncovered. Noether's 1918 paper developed Hilbert's and Klein's reflections on the conservation laws. Energy-momentum is just a term proportional…

History and Philosophy of Physics · Physics 2019-09-16 J. Brian Pitts

In this paper, we study the equation of state and its properties of the perfect fluid in the $D$-dimensional FRW universe under Einstein gravity, Gauss-Bonnet gravity and Lovelock gravity. In Einstein gravity, we get the equation of state…

General Relativity and Quantum Cosmology · Physics 2025-12-19 Shi-Bei Kong , Ying Wang , Yu-Ke Wang