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Related papers: Friedmann equations for deformed entropic gravity

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A new class of exact solutions of Einstein's field equations with a perfect fluid source, variable gravitational coupling $G$ and cosmological term $\Lambda$ for FRW spacetime is obtained by considering variable deceleration parameter…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Anirudh Pradhan , Ajay Kumar Singh , Saeed Otarod

Non-perturbative studies of quantum gravity have recently suggested the possibility that the strength of gravitational interactions might slowly increase with distance. Here a set of generally covariant effective field equations are…

High Energy Physics - Theory · Physics 2011-07-19 Herbert W. Hamber , Ruth M. Williams

Einstein equations can be written in the so-called Fully Constrained Formulation (FCF). This formulation has two different sectors: the elliptic sector, formed by the Hamiltonian and Momentum constraints together with the equations derived…

General Relativity and Quantum Cosmology · Physics 2025-07-25 Samuel Santos-Pérez , Isabel Cordero-Carrión , Pablo Cerdá-Durán

We study the present, flat isotropic universe in 1/R-modified gravity. We use the Palatini (metric-affine) variational principle and the Einstein (metric-compatible connected) conformal frame. We show that the energy density scaling…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Nikodem J. Poplawski

Einstein field equations with a cosmological constant are approximated to the second order in the perturbation to a flat background metric. The final result is a set of Einstein-Maxwell-Proca equations for gravity in the weak field regime.…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Clovis Jacinto de Matos

Generic relevant deformations of Einstein's gravity theory contain additional degrees of freedom that have a multi-facetted stabilization dynamics on curved spacetimes. We show that these relevant degrees of freedom are self-protected…

High Energy Physics - Theory · Physics 2011-05-23 Felix Berkhahn , Dennis D. Dietrich , Stefan Hofmann

We present approximate exterior and interior solutions of Einstein's equations which describe the gravitational field of a static deformed mass distribution. The deformation of the source is taken into account up to the first order in the…

General Relativity and Quantum Cosmology · Physics 2016-03-16 Medeu Abishev , Kuantay Boshkayev , Hernando Quevedo , Saken Toktarbay

Considering the Friedmann--Lema\^{i}tre--Robertson--Walker (FLRW) metric and the Einstein scalar field system as an underlying gravitational model to construct fractional cosmological models has interesting implications in both classical…

General Relativity and Quantum Cosmology · Physics 2024-07-26 S. M. M. Rasouli , S. Cheraghchi , P. V. Moniz

In this work we consider a recent proposal in which gravitational interactions are mediated via classical information and apply it to a relativistic context. We study a toy model of a quantized Friedman-Robertson-Walker (FRW) universe with…

General Relativity and Quantum Cosmology · Physics 2017-05-31 Natacha Altamirano , Paulina Corona-Ugalde , Kiran Khosla , Robert B. Mann , Gerard Milburn

In this paper, combining the thermodynamical arguments of the horizon with the quadratic generalised uncertainty principle (GUP), we heuristically obtain the modified equipartition law of energy. Employing this modified equipartition law of…

General Relativity and Quantum Cosmology · Physics 2025-11-21 Özgür Ökcü

Gravity is perturbatively renormalizable for the physical states which can be conveniently defined via foliation-based quantization. In recent sequels, one-loop analysis was explicitly carried out for Einstein-scalar and Einstein-Maxwell…

High Energy Physics - Theory · Physics 2021-11-12 I. Y. Park

Recently, Verlinde proposed that gravity is an emergent phenomenon which originates from an entropic force. In this work, we extend Verlinde's proposal to accommodate generalized uncertainty principles (GUP), which are suggested by some…

General Relativity and Quantum Cosmology · Physics 2024-09-20 Adel Awad , Ahmed Farag Ali

In this work we study how nonminimally coupled theories of gravity modify the usual Friedmann equation, and develop two methods to treat these. The ambiguity in the form of the Lagrangian density of a perfect fluid is emphasized, and the…

General Relativity and Quantum Cosmology · Physics 2015-06-18 Orfeu Bertolami , Jorge Páramos

A generalized geometric method is developed for constructing exact solutions of gravitational field equations in Einstein theory and generalizations. First, we apply the formalism of nonholonomic frame deformations (formally considered for…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Sergiu I. Vacaru

This paper starts from a toy model for inflation in a class of modified theories of gravity in the metric formalism. Instead of the standard procedure -- assuming a non-linear Lagrangian $f(R)$ in the Jordan frame -- we start from a simple…

General Relativity and Quantum Cosmology · Physics 2020-07-01 C. D. Peralta , S. E. Jorás

We study self-consistent cosmological solutions for an Einstein universe in a graph-based induced gravity model. Especially, we demonstrate specific results for cycle graphs.

General Relativity and Quantum Cosmology · Physics 2007-12-27 Nahomi Kan

In this paper we use the conformal teleparallel gravity to study an isotropic and homogeneous Universe which is settled by the FRW metric. We solve the field equations and we obtain the behavior of some cosmological parameters such as scale…

General Relativity and Quantum Cosmology · Physics 2016-03-30 J. G. Silva , A. F. Santos , S. C. Ulhoa

There is a distinct possibility that current and future cosmological data can be used to constrain Einstein's theory of gravity on the very largest scales. To be able to do this in a model-independent way, it makes sense to work with a…

Cosmology and Nongalactic Astrophysics · Physics 2012-01-13 Tessa Baker , Pedro G. Ferreira , Constantinos Skordis , Joe Zuntz

This work is the extension of author`s research, where the modified theory of induced gravity (MTIG) is proposed. The theory describes two systems (stages): Einstein (ES) and "restructuring" (RS). We consider equations with quadratic…

General Physics · Physics 2019-11-22 Farkhat Zaripov

We consider a minimal fractional deformation of Newtonian gravity characterized by a single parameter $\alpha$. In the limit $\alpha \to 1$, the theory reduces to standard Newtonian gravity. Previous works showed that the $\Lambda$CDM…

General Relativity and Quantum Cosmology · Physics 2026-03-18 S. M. M. Rasouli