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We present a gravitational quantum dynamics theory that combines quantum field theory for particle dynamics in space-time with classical Einstein's general relativity in a non-Riemannian Finsler space. This approach is based on the…

General Relativity and Quantum Cosmology · Physics 2021-01-05 Ivano Tavernelli

At the mesoscopic scales --- which interpolate between the macroscopic, classical, geometry and the microscopic, quantum, structure of spacetime --- one can identify the density of states of the geometry which arises from the existence of a…

General Relativity and Quantum Cosmology · Physics 2018-12-19 T. Padmanabhan

In this talk r-form fields in spacetimes of any dimension D are considered (r<D). The weak-field Newtonian-type limit of Einstein's equations, in general, with relativistic sources is studied in the static case yielding a revision of the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Nikolai V. Mitskievich

We discuss and expand a new approach to the thermodynamics of scalar-tensor gravity and its diffusion toward general relativity (seen as an equilibrium state) proposed in a previous Letter [Phys. Rev. D 103, L121501 (2021)], upon which we…

General Relativity and Quantum Cosmology · Physics 2022-01-05 Valerio Faraoni , Andrea Giusti , Andrea Mentrelli

Einstein's equations in matter are gravitational analogues of Maxwell's equations in matter, providing an effective classical description of gravitational fields. We derive Einstein's equations in matter for relativistic fluids, and use…

General Relativity and Quantum Cosmology · Physics 2020-05-29 Pavel Kovtun , Ashish Shukla

A calculation by Jacobson [1] strongly implies that the field equations which describe gravity are emergent phenomena. In this paper, the method is extended to the case of a non-commutative spacetime. By making use of a non-commutative…

High Energy Physics - Theory · Physics 2015-05-21 Simon Moolman

A new principle in quantum gravity, dubbed spacetime complexity, states that gravitational physics emerges from spacetime seeking to optimize the computational cost of its quantum dynamics. Thus far, this principle has been realized at the…

High Energy Physics - Theory · Physics 2023-09-29 Rafael Carrasco , Juan F. Pedraza , Andrew Svesko , Zachary Weller-Davies

We analyze the isothermal property in static fluid spheres within the framework of the modified $f(R, T)$ theory of gravitation. The equation of pressure isotropy of the standard Einstein theory is preserved however, the energy density and…

General Relativity and Quantum Cosmology · Physics 2018-09-26 Sudan Hansraj

It has previously been shown that the Einstein equation can be derived from the requirement that the Clausius relation dS = dQ/T hold for all local acceleration horizons through each spacetime point, where dS is one quarter the horizon area…

General Relativity and Quantum Cosmology · Physics 2011-05-05 Christopher Eling , Raf Guedens , Ted Jacobson

Recent works have demonstrated that one can construct a (d+2) dimensional solution of the vacuum Einstein equations that is dual to a (d+1) dimensional fluid satisfying the incompressible Navier-Stokes equations. In one important example,…

High Energy Physics - Theory · Physics 2011-08-05 Goffredo Chirco , Christopher Eling , Stefano Liberati

Research during the last one decade or so suggests that the gravitational field equations in a large class of theories (including, but not limited to, general relativity) have the same status as the equations of, say, gas dynamics or…

General Relativity and Quantum Cosmology · Physics 2015-06-23 T. Padmanabhan

We define thermodynamic pressure $P$ by work density $W$ as the conjugate quantity of thermodynamic volume $V$ from field equation. We derive the equations of state $P$=$P(V, T)$ for the Friedmann-Robertson-Walker (FRW) universe in Einstein…

General Relativity and Quantum Cosmology · Physics 2022-11-28 Shi-Bei Kong , Haximjan Abdusattar , Yihao Yin , Hongsheng Zhang , Ya-Peng Hu

We consider plane-symmetric spacetimes satisfying Einstein's field equations with positive cosmological constant, when the matter is a fluid whose pressure is equal to its mass-energy density (i.e. a so-called stiff fluid). We study the…

General Relativity and Quantum Cosmology · Physics 2012-05-01 Philippe G. LeFloch , Sophonie B. Tchapnda

In this paper we assume that a perfect fluid is the source of the gravitational field while analyzing the solutions to the Einstein field equations.

General Relativity and Quantum Cosmology · Physics 2024-02-26 Krishnendu De , Uday Chand De , Ljubica Velimirovic

We study the solutions of the semiclassical Einstein equation in flat cosmological spacetimes driven by a massive conformally coupled scalar field. In particular, we show that it is possible to give initial conditions at finite time to get…

Mathematical Physics · Physics 2015-03-10 Nicola Pinamonti , Daniel Siemssen

One of the striking features of general relativity is that the Einstein equation is implied by the Clausius relation imposed on a small patch of locally constructed causal horizon. Extension of this thermodynamic derivation of the field…

General Relativity and Quantum Cosmology · Physics 2016-08-17 Ramit Dey , Stefano Liberati , Arif Mohd

Einstein's theory of general relativity describes gravity as the interaction of particles with space-time geometry, as opposed to interacting with a physical fluid, as in the old gravitational aether theories. Moreover, any theoretical…

Popular Physics · Physics 2010-04-19 Niayesh Afshordi

A new entropic gravity inspired derivation of general relativity from thermodynamics is presented. This generalizes, within Einstein gravity, the "Thermodynamics of Spacetime" approach by T. Jacobson, which relies on the Raychaudhuri…

High Energy Physics - Theory · Physics 2016-08-05 Ian Nagle

This research is an extension of the author's article \cite{zar}, in which conformally invariant generalization of string theory was suggested to higher-dimensional objects. Special cases of the proposed theory are Einstein's theory of…

General Relativity and Quantum Cosmology · Physics 2014-10-13 Farkhat Zaripov

This paper deals with the evolution of the Einstein gravitational fields which are coupled to a perfect fluid. We consider the Einstein--Euler system in asymptotically flat spacestimes and therefore use the condition that the energy density…

Analysis of PDEs · Mathematics 2013-05-10 Uwe Brauer , Lavi Karp