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Related papers: Entropic f(R) Gravity

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In previous works, entropic gravity and ungravity have been considered as possible solutions to the dark energy and dark matter problems. To test the viability of these models, modifications to planetary orbits are calculated for ungravity…

General Relativity and Quantum Cosmology · Physics 2025-10-09 G. Pérez Cuéllar , M. Sabido

A cosmological constant in the regime of low space-time curvature is calculated in the recently proposed version of F(R) supergravity with a generic cubic function F. The F(R) supergravity is the N=1 supersymmetric extension of f(R)…

High Energy Physics - Theory · Physics 2015-05-30 Sergei V. Ketov , Natsuki Watanabe

The role of torsion in f(R) gravity is considered in the framework of metric-affine formalism. We discuss the field equations in empty space and in presence of perfect fluid matter taking into account the analogy with the Palatini…

General Relativity and Quantum Cosmology · Physics 2008-11-26 S. Capozziello , R. Cianci , C. Stornaiolo , S. Vignolo

While most fundamental interactions in nature are known to be mediated by quantized fields, the possibility has been raised that gravity may behave differently. Making this concept precise enough to test requires consistent models. Here we…

Quantum Physics · Physics 2023-01-23 Daniel Carney , Jacob M. Taylor

Explicit tests are presented of the conjectured entropic origin of the gravitational force. The gravitational force on a test particle in the vicinity of the horizon of a large Schwarzschild black hole in arbitrary spacetime dimensions is…

General Relativity and Quantum Cosmology · Physics 2018-08-08 Sourav Bhattacharya , Panagiotis Charalambous , Theodore N Tomaras , Nicolaos Toumbas

We propose the mimetic $F(R)$ theory and investigate the early-time and late-time acceleration in such theory. It is demonstrated that inflation consistent with observable data may be realized in such theory. The reconstruction of realistic…

High Energy Physics - Theory · Physics 2014-12-19 Shin'ichi Nojiri , Sergei D. Odintsov

We review different approaches to quantum gravity in which spacetime is emerging. We discuss in some detail the proposals by G. Volovik and S. Lloyd and show how they differ in the way they treat time. We further propose an approach to…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Olaf Dreyer

The field equations of a generalized $f(R)$ type gravity model, in which there is an arbitrary coupling between matter and geometry, are obtained. The equations of motion for test particles are derived from a variational principle in the…

General Relativity and Quantum Cosmology · Physics 2009-05-26 T. Harko

Anisotropic cosmological models are investigated in the frame work of $f(R)$ gravity in the metric formalism. Plane symmetric models are considered to incorporate anisotropy in the expansion rates along different spatial directions. The…

General Relativity and Quantum Cosmology · Physics 2017-04-26 S K Tripathy , B Mishra

We derive the equation of matter density perturbations on sub-horizon scales around a flat Friedmann-Lema\^\i tre-Robertson-Walker background for the general Lagrangian density $f(R,\GB)$ that is a function of a Ricci scalar $R$ and a…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-13 Antonio De Felice , Teruaki Suyama

We derive the equations of state of Fermi gas by maximizing the Fermi-Dirac entropy in modified gravity in relativistic and non-relativistic case. It will be demonstrated that the microphysics must depend on a given theory of gravity in…

General Relativity and Quantum Cosmology · Physics 2023-02-14 Aneta Wojnar

Modified theories of gravity have been invoked recently as an alternative to dark energy, in an attempt to explain the apparent accelerated expansion of the universe at the present time. In order to describe inhomogeneities in cosmological…

General Relativity and Quantum Cosmology · Physics 2016-04-15 Adam J. Christopherson

In gravity theories derived from a f(R) Lagrangian, matter is usually supposed to be minimally coupled to the metric, which hence defines a ``Jordan frame.'' However, since the field equations are fourth order, gravity possesses an extra…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Nathalie Deruelle , Misao Sasaki , Yuuiti Sendouda

Entropic Dynamics is an information-based framework that seeks to derive the laws of physics as an application of the methods of entropic inference. The dynamics is derived by maximizing an entropy subject to constraints that represent the…

Quantum Physics · Physics 2015-06-23 Selman Ipek , Ariel Caticha

In this paper, we consider a theory of gravity with a metric-dependent torsion namely the $F(R,T)$ gravity, where $R$ is the curvature scalar and $T$ is the torsion scalar. We study a geometric root of such theory. In particular we give the…

General Relativity and Quantum Cosmology · Physics 2012-11-20 Ratbay Myrzakulov

Entropic Dynamics is a framework in which quantum theory is derived as an application of entropic methods of inference. There is no underlying action principle. Instead, the dynamics is driven by entropy subject to the appropriate…

Quantum Physics · Physics 2015-06-23 Ariel Caticha , Daniel Bartolomeo , Marcel Reginatto

A vast concourse of events and phenomena occur in nature that may be interrelated by a entropy-maximization technique that provides a comprehensible explanation of a range of physical problems, integrating in a new framework the universal…

Classical Physics · Physics 2021-10-18 Mario J Pinheiro

The phenomenological description of the cosmological particle production in the framework of the induced gravity is investigated. It appears that the source terms with the particle number density in the creation law can be interpreted as…

General Relativity and Quantum Cosmology · Physics 2024-12-17 V. A. Berezin , I. D. Ivanova , A. E. Kuprina

This paper is a set of notes that we wrote concerning the first version of Emergent Gravity [gr-qc/0602022]. It is our version of an exercise that we proposed to some of our students. The idea was to find mathematical errors and…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Waldyr A. Rodrigues

A theory of gravity with torsion is examined in which the torsion tensor is constructed from the exterior derivative of an antisymmetric rank two potential plus the dual of the gradient of a scalar field. Field equations for the theory are…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Charro Gruver , Richard Hammond , P. F. Kelly
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