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Related papers: f(G) modified gravity and the energy conditions

200 papers

The aim of this paper is to reconstruct and analyze the stability of some cosmological models against linear perturbations in $f(\mathcal{G},T)$ gravity ($\mathcal{G}$ and $T$ represent the Gauss-Bonnet invariant and trace of the…

General Relativity and Quantum Cosmology · Physics 2017-06-22 M. Sharif , Ayesha Ikram

We consider class of modified $f(R)$ gravities with the effective cosmological constant epoch at the early and late universe. Such models pass most of solar system tests as well they satisfy to cosmological bounds. Despite their very…

High Energy Physics - Theory · Physics 2008-11-26 Shin'ichi Nojiri , Sergei D. Odintsov

We study finite-time future singularities in $\mathcal{F}(R,G)$-gravity, where $R$ and $G$ are the Ricci scalar and the Gauss-Bonnet invariant, respectively. In particular, we reconstruct the $F(G)$-gravity and $\mathcal{F}(R,G)$-gravity…

General Relativity and Quantum Cosmology · Physics 2015-05-19 Lorenzo Sebastiani

We explore cosmological perturbations in a modified Gauss-Bonnet f(G) gravity, using a 1+3 covariant formalism. In such a formalism, we define gradient variables to get perturbed linear evolution equations. We transform these linear…

General Relativity and Quantum Cosmology · Physics 2022-09-20 Albert Munyeshyaka , Joseph Ntahompagaze , Tom Mutabazi

A modified Mimetic gravity (MMG) is proposed as a generalization of general relativity. The model contain a physical metric which is function of an auxiliary (unphysical) metric and a Lyra's metric. We construct different kinds of…

General Relativity and Quantum Cosmology · Physics 2015-04-07 Davood Momeni , Aziza Altaibayeva , Ratbay Myrzakulov

We review the status of $f(R,T)$ cosmological models, where $T$ is the trace of the energy momentum tensor $T^{\mu\nu}$. We start focusing on the modified Friedmann equations for the minimally coupled gravitational Lagrangian of the type…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-08 Ana Paula Jeakel , Jonas Pinheiro da Silva , Hermano Velten

Theoretical arguments and cosmological observations suggest that Einstein's theory of general relativity needs to be modified at high energies. One of the best motivated higher-curvature extensions of general relativity is…

General Relativity and Quantum Cosmology · Physics 2017-08-04 Laura Sberna

We propose, in a heuristic way, a relativistic modified gravity model as an alternative to particle dark matter at galactic scales. The model is based on a postulated preferred time foliation described by a dynamical scalar field called the…

General Relativity and Quantum Cosmology · Physics 2015-05-28 Luc Blanchet , Sylvain Marsat

Within the context of modified gravity and dark energy scenarios of the accelerating universe, we study the stability of de Sitter space with respect to inhomogeneous perturbations using a gauge-independent formalism. In modified gravity…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Valerio Faraoni

There is now overwhelming observational evidence that our Universe is accelerating in its expansion. I discuss how modified gravitational models can provide an explanation for this observed late-time cosmic acceleration. We consider…

Astrophysics · Physics 2008-11-26 Damien A. Easson

We present a novel approach for reconstructing the $f(Q)$ gravitational theory using parameterizations of the deceleration parameter or alternative options. This method enables the development of modified gravity scenarios that align with…

General Relativity and Quantum Cosmology · Physics 2025-02-26 G. G. L. Nashed

We investigate cosmological perturbations of f(G) gravity in the presence of a scalar field. Using the 1 + 3 covariant formalism, we present the energy overdensity perturbation equations responsible for large scale structure formation.…

General Relativity and Quantum Cosmology · Physics 2023-12-27 Albert Munyeshyaka , Joseph Ntahompagaze , Tom Mutabazi , Manasse. R Mbonye

In analogy to $f(R)$ theory, recently a new modified gravity theory, namely the so-called $f(T)$ theory, has been proposed to drive the current accelerated expansion without invoking dark energy. In the present work, by extending Bisabr's…

General Relativity and Quantum Cosmology · Physics 2011-08-25 Hao Wei , Xiao-Peng Ma , Hao-Yu Qi

We study cosmology in a class of minimally modified gravity (MMG) with two local gravitational degrees of freedom. We classify modified gravity theories into type-I and type-II: theories of type-I have an Einstein frame and can be recast by…

General Relativity and Quantum Cosmology · Physics 2019-01-16 Katsuki Aoki , Antonio De Felice , Chunshan Lin , Shinji Mukohyama , Michele Oliosi

In this paper we address the issue of exploring some cosmological scenarios in modified Einstein gravity through non-dynamical (auxiliary) fields. We found that all scenarios are controlled by a specific parameter associated with an…

High Energy Physics - Theory · Physics 2014-08-27 D. Bazeia , F. A. Brito , F. G. Costa

We consider a DGP brane scenario where a scalar field is present on the brane through the introduction of a scalar potential, itself motivated by the notion of modified gravity. This theory predicts that the mass appearing in the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 K. Atazadeh , H. R. Sepangi

Modified Newtonian dynamics, a successful alternative to the cosmic dark matter model, proposes that gravitational field deviates from the Newtonian law when the field strength $g$ is weaker than a critical value $g_0$. We will show that…

General Relativity and Quantum Cosmology · Physics 2007-05-23 W. F. Kao

In modern cosmology, the curiosity of ultimately understanding the nature of the dark energy controlling the recent acceleration of the Universe motivates us to explore its properties by using some novel approaches. In this work, to explore…

General Relativity and Quantum Cosmology · Physics 2023-12-19 Sanjay Mandal , Sneha Pradhan , P. K. Sahoo , Tiberiu Harko

The late-time acceleration of the universe remains one of the most significant open problems in modern cosmology. Modified gravity frameworks such as $f(T)$ gravity provide a geometric alternative to dark energy by attributing cosmic…

General Relativity and Quantum Cosmology · Physics 2026-05-07 Anirudh Pradhan , S. A. Salve , V. B. Raut , S. H. Shekh

In this paper we study the final fate of the universe in modified theories of gravity. As compared with general relativistic formulations, in these scenarios the Friedmann equation has additional terms which are relevant for low density…

General Relativity and Quantum Cosmology · Physics 2009-01-16 L. Fernández-Jambrina , Ruth Lazkoz