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Related papers: Extended Theories of Gravity with Generalized Ener…

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We consider generalized energy conditions in modified theories of gravity by taking into account the further degrees of freedom related to scalar fields and curvature invariants. The latter are usually recast as generalized {\it geometrical…

General Relativity and Quantum Cosmology · Physics 2014-02-14 Salvatore Capozziello , Francisco S. N. Lobo , José P. Mimoso

Theories of physics can be considered viable if the initial value problem and the energy conditions are formulated self-consistently. The former allow a uniquely determined dynamical evolution of the system, and the latter guarantee that…

General Relativity and Quantum Cosmology · Physics 2015-06-08 Salvatore Capozziello , Francisco S. N. Lobo , José P. Mimoso

We discuss the validity of the energy conditions in a newly modified theory named as $f(R,T,R_{\mu\nu}T^{\mu\nu})$ gravity, where $R$ and $T$ represent the scalar curvature and trace of the energy-momentum tensor. The corresponding energy…

General Relativity and Quantum Cosmology · Physics 2014-02-20 M. Sharif , M. Zubair

The study of energy conditions has many significant applications in general relativistic and cosmological contexts. This paper explores the energy conditions in the framework of the most general scalar-tensor theory with field equations…

General Relativity and Quantum Cosmology · Physics 2013-11-27 M. Sharif , Saira Waheed

The aim of this paper is to introduce a new modified gravity theory named as $f(\mathcal{G},T)$ gravity ($\mathcal{G}$ and $T$ are the Gauss-Bonnet invariant and trace of the energy-momentum tensor, respectively) and investigate energy…

General Relativity and Quantum Cosmology · Physics 2016-12-21 M. Sharif , Ayesha Ikram

Extended Theories of Gravity can be considered a new paradigm to cure shortcomings of General Relativity at infrared and ultraviolet scales. They are an approach that, by preserving the undoubtedly positive results of Einstein's Theory, is…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Salvatore Capozziello , Mariafelicia De Laurentis

Towards the goal to quantize gravity, in this short review we discuss an intermediate step which consists in extending the picture of standard General Relativity by considering Extended Theories of Gravity. In this tapestry, the equations…

General Relativity and Quantum Cosmology · Physics 2014-03-03 Christian Corda

In standard approach to cosmological modeling in the framework of general relativity, the energy conditions play an important role in the understanding of several properties of the Universe, including singularity theorems, the current…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-10 Di Liu , M. J. Reboucas

$f(P)$ gravity is a novel extension of ECG in which the Ricci scalar in the action is replaced by a function of the curvature invariant $P$ which represents the contractions of the Riemann tensor at the cubic order \cite{p}. The present…

General Relativity and Quantum Cosmology · Physics 2022-03-29 Snehasish Bhattacharjee

Modified gravity is one of the most favorable candidates for explaining the current accelerating expansion of the Universe. In this regard, we study the viability of an alternative gravitational theory, namely $f(R,G)$, by imposing energy…

General Relativity and Quantum Cosmology · Physics 2014-01-30 K. Atazadeh , F. Darabi

We study and derive the energy conditions in generalized non-local gravity, which is the modified theory of general relativity (GR) obtained by adding a term $m^{2n-2}R\Box^{-n}R$ to the Einstein-Hilbert action. Moreover, in order to get…

General Relativity and Quantum Cosmology · Physics 2017-08-02 Ya-Bo Wu , Xue Zhang , Bo-Hai Chen , Nan Zhang , Meng-Meng Wu

The present paper examines the validity of energy bounds in a modified theory of gravity involving non-minimal coupling of torsion scalar and perfect fluid matter. In this respect, we formulate the general inequalities of energy conditions…

General Relativity and Quantum Cosmology · Physics 2015-02-11 M. Zubair , Saira Waheed

In considering alternative higher-order gravity theories, one is liable to be motivated in pursuing models consistent and inspired by several candidates of a fundamental theory of quantum gravity. Indeed, motivations from string/M-theory…

General Relativity and Quantum Cosmology · Physics 2015-03-17 Nadiezhda Montelongo García , Tiberiu Harko , Francisco S. N. Lobo , José P. Mimoso

Inspired by Verlinde's idea, some modified versions of entropic gravity have appeared in the literature. Extending them in a unified formalism, we derive the generalized gravitational equations accordingly. From gravitational equations, the…

High Energy Physics - Theory · Physics 2012-11-27 Tower Wang

Dark energy dynamics of the universe can be achieved by equivalent mathematical descriptions taking into account generalized fluid equations of state in General Relativity, scalar-tensor theories or modified F(R) gravity in Einstein or…

High Energy Physics - Theory · Physics 2008-11-26 S. Capozziello , S. Nojiri , S. D. Odintsov

In Phys. Rev. D 102, 024057 (2020), the authors studied energy conditions in $f(Q)$ theory following the same path as researchers handled the energy conditions in the curvature-based modified gravity theories, like $f(R)$ or $f(R,G)$…

General Relativity and Quantum Cosmology · Physics 2022-09-14 Avik De , Loo Tee How

An energy condition, in the context of a wide class of spacetime theories (including general relativity), is, crudely speaking, a relation one demands the stress-energy tensor of matter satisfy in order to try to capture the idea that…

History and Philosophy of Physics · Physics 2021-03-04 Erik Curiel

A modified f(G) gravity model with coupling between matter and geometry is proposed, which is described by the product of the Lagrange density of the matter and an arbitrary function of the Gauss-Bonnet term. The field equations and the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Yue-Yue Zhao , Ya-Bo Wu , Jianbo Lu , Zhuo Zhang , Wei-Li Han , Liang-Liang Ling

From a previous paper where we proposed a description of general relativity within the gravito-electromagnetic limit, we propose an alternative modified gravitational theory. As in the former version, we analyze the vector and tensor…

General Relativity and Quantum Cosmology · Physics 2022-05-03 Sergio Giardino

Modern astrophysical and cosmological models are plagued with two severe theoretical difficulties, namely, the dark energy and the dark matter problems. Relative to the former, high-precision observational data have confirmed with startling…

General Relativity and Quantum Cosmology · Physics 2015-05-05 Francisco S. N. Lobo
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