English
Related papers

Related papers: Off-diagonal solutions in Einsteingravity modeling…

200 papers

This review explores modified theories of gravity, particularly $f(R)$ gravity, as extensions to General Relativity (GR) that offer alternatives to dark energy for explaining cosmic acceleration. These models generalize the Einstein-Hilbert…

General Relativity and Quantum Cosmology · Physics 2025-03-05 Rafid H. Dejrah

The recent discovery of gravitational waves marks the culmination of a sequence of successful tests of the general theory of relativity (GR) since its formulation in 1915. Yet these tests remain confined to the scale of stellar systems or…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-10 Jian-hua He , Luigi Guzzo , Baojiu Li , Carlton M. Baugh

Over the past century, General Relativity (GR) has been a cornerstone of gravitational theory. However, recent cosmological observations, such as the accelerated expansion of the Universe, challenge its completeness and the standard…

General Relativity and Quantum Cosmology · Physics 2025-06-02 Lakhan V. Jaybhaye

This paper is devoted to investigate the recently proposed modified Gauss-Bonnet $f(\mathcal{G},T)$ gravity, with $\mathcal{G}$, the Gauss-Bonnet term, coupled with ${T}$, the trace of energy-momentum tensor. We have used the Noether…

General Relativity and Quantum Cosmology · Physics 2017-07-12 M. Farasat Shamir , Mushtaq Ahmad

A number of recent observations have suggested that the Einstein's theory of general relativity may not be the ultimate theory of gravity. The f(R) gravity model with R being the scalar curvature turns out to be one of the best bet to…

General Relativity and Quantum Cosmology · Physics 2019-11-26 Surajit Kalita , Banibrata Mukhopadhyay

We consider predictions for structure formation from modifications to general relativity in which the Einstein-Hilbert action is replaced by a general function of the Ricci scalar. We work without fixing a gauge, as well as in explicit…

Astrophysics · Physics 2010-04-06 Rachel Bean , David Bernat , Levon Pogosian , Alessandra Silvestri , Mark Trodden

In this work, we present a method for numerically solving the Friedmann equations of modified $f(\mathcal{G})$ gravity in the presence of pressureless matter. This method enables us to predict the redshift behaviour of the Hubble expansion…

General Relativity and Quantum Cosmology · Physics 2024-11-08 Santosh V. Lohakare , Soumyadip Niyogi , B. Mishra

We propose a new approach to the quasitopological theory of gravity based on a modified classical double--copy construction. Focusing on static, spherically symmetric configurations, we show that all vacuum solutions of $D$--dimensional…

General Relativity and Quantum Cosmology · Physics 2026-01-08 Valeri P. Frolov

The gravitational equations of the three dimensional (3D) brane world are investigated for both off-diagonal and warped 5D metrics which can be diagonalized with respect to some anholonomic frames when the gravitational and matter fields…

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

A modified f(R) gravity model has been recently proposed in Phys. Rev. Lett. 102, 221101 (2009) [arXiv:0905.1941] whose cosmological behaviour is clearly distinguishable from LCDM. Contrary to previous opinions which consider that…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-29 A. de la Cruz-Dombriz , A. Dobado , A. L. Maroto

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

The standard paradigm of cosmology assumes General Relativity (GR) is a valid theory for gravity at scales in which it has not been properly tested. Developing novel tests of GR and its alternatives is crucial if we want to give strength to…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-22 Claudio Llinares

Modified gravity has attracted much attention over the last few years and remains a potential candidate for dark energy. In particular, the so-called viable f(R) gravity theories, which are able to both recover General Relativity (GR) and…

General Relativity and Quantum Cosmology · Physics 2016-04-20 Alvaro de la Cruz-Dombriz , Peter K. S. Dunsby , Sulona Kandhai , Diego Saez-Gomez

A new framework to perturbative quantum gravity is proposed following the geometry of nonholonomic distributions on (pseudo) Riemannian manifolds. There are considered such distributions and adapted connections, also completely defined by a…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Sergiu I. Vacaru

We elaborate on a model of nonassociative and noncommutative Einstein--Dirac-Maxwell, EDM, theory determined by star product R-flux deformations in string theory. Solutions for nonassociative EDM systems and physical properties not studied…

High Energy Physics - Theory · Physics 2024-10-08 L. Bubuianu , J. O. Seti , S. Vacaru , E. V. Veliev

In this work, we investigate the cosmological consequences of an effective $f(Q)$ model emerging from the more general $f(Q,T)$ gravity theory under the special equation-of-state condition $\rho + p = 0$. Under this limit, the field…

General Relativity and Quantum Cosmology · Physics 2025-12-12 Anil Kumar Yadav , S. H. Shekh , N. Myrzakulov

This study conducts a meticulous examination of the cosmological implications inherent in Rastall gravity and $f(R)$ gravity models, assessing their efficacy across distinct cosmic epochs, from early universe structure formation to…

General Relativity and Quantum Cosmology · Physics 2025-01-14 Muhammad Yarahmadi , Amin Salehi , Hadis Mousavi

A geometric procedure is elaborated for transforming (pseudo) Riemanian metrics and connections into canonical geometric objects (metric and nonlinear and linear connections) for effective Lagrange, or Finsler, geometries which, in their…

Mathematical Physics · Physics 2012-01-25 Sergiu I. Vacaru

We revise general relativity (GR) from the perspective of calculus for moving surfaces (CMS). While GR is intrinsically constructed in pseudo-Riemannian geometry, a complete understanding of moving manifolds requires embedding in a higher…

General Relativity and Quantum Cosmology · Physics 2024-06-13 David V. Svintradze

Modified gravity theories with the Gauss-Bonnet term $G=R^2-4R^{\mu\nu}R_{\mu\nu}+R^{\mu\nu\rho\sigma}R_{\mu\nu\rho\sigma}$ have recently gained a lot of attention as a possible explanation of dark energy. We perform a thorough phase space…

General Relativity and Quantum Cosmology · Physics 2010-10-01 Shuang-Yong Zhou , Edmund J. Copeland , Paul M. Saffin