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In general relativity, the energy conditions are invoked to restrict general energy-momentum tensors on physical grounds. We show that in the standard Friedmann-Lemaitre-Robertson-Walker approach to cosmological modelling where the equation…

Astrophysics · Physics 2009-11-11 J. Santos , J. S. Alcaniz , M. J. Reboucas

In general relativity, the energy conditions are invoked to restrict general energy-momentum tensors on physical grounds. We show that in the standard Friedmann-Lemaitre-Robertson-Walker (FLRW) approach to cosmological modeling, where the…

Astrophysics · Physics 2008-12-18 J. Santos , J. S. Alcaniz , M. J. Reboucas , N. Pires

In the standard Friedmann-Lemaitre-Robertson-Walker (FLRW) approach to model the Universe the violation of the so-called energy conditions is related to some important properties of the Universe as, for example, the current and the…

Astrophysics · Physics 2016-03-28 M. P. Lima , S. D. P. Vitenti , M. J. Reboucas

The energy conditions play an important role in the understanding of several properties of the Universe, including the current accelerating expansion phase and the possible existence of the so-called phantom fields. We show that the…

Astrophysics · Physics 2009-06-23 M. P. Lima , S. Vitenti , M. J. Reboucas

In the standard Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmological model, the energy conditions provides model-independent bounds on the behavior of the distance modulus. However, this method can not provide us the detailed information…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-20 Wen-Fei Liu , Jing Niu , Juan Li , Tong-Jie Zhang

We are experiencing a golden age of experimental cosmology, with exact and accurate observations being used to constrain various gravitational theories like never before. Alongside these advancements, energy conditions play a crucial…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-08 Y. Myrzakulov , O. Donmez , M. Koussour , S. Muminov , D. Ostemir , J. Rayimbaev

The energy conditions of Einstein gravity (classical general relativity) are designed to extract as much information as possible from classical general relativity without enforcing a particular equation of state for the stress-energy. This…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Matt Visser

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

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 four principal energy conditions (ECs) in general relativity prohibit negative energies, repulsive gravity and superluminal energy flows. One must invoke exotic matter to violate any one of these, yet $\Lambda$CDM does so quite…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-29 Namit Chandak , Fulvio Melia , Junjie Wei

In this exclusive study of the modified $f(Q)$ theory of gravity in the open and closed type Friedmann-Lema\^itre-Robertson-Walker (FLRW) universe model, we impose some constraints from the classical energy conditions. The viable range of…

General Relativity and Quantum Cosmology · Physics 2023-06-07 Ganesh Subramaniam , Avik De , Tee-How Loo , Yong Kheng Goh

In order to shed some light on the current discussion about f(R)-gravity theories we derive and discuss the bounds imposed by the energy conditions on a general f(R) functional form. The null and strong energy conditions in this framework…

Astrophysics · Physics 2008-11-26 J. Santos , J. S. Alcaniz , M. J. Reboucas , F. C. Carvalho

In this paper, we investigate the energy conditions (including null, weak, strong, dominant) in generalized teleparallel gravities including pure $F(T)$, teleparallel gravity with non-minimally coupled scalar field and $F(T)$ with…

General Physics · Physics 2013-01-08 Mubasher Jamil , D. Momeni , Ratbay Myrzakulov

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

In today's scenario, going beyond Einstein's theory of gravity leads us to some more complete and modified gravity theories. One of them is the $f(R,T)$ gravity in which $ R $ is the Ricci scalar, and $ T $ is the trace of the…

General Relativity and Quantum Cosmology · Physics 2022-01-04 P. K. Sahoo , Sanjay Mandal , Simran Arora

The energy conditions are derived in the context of $f(R,T)$ gravity, where $R$ is the Ricci scalar and $T$ is the trace of the energy-momentum tensor, which can reduce to the well-known conditions in $f(R)$ gravity and general relativity.…

General Relativity and Quantum Cosmology · Physics 2015-06-11 Muhammad Sharif , Muhammad Zubair

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

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 energy conditions of Einstein gravity (classical general relativity) do not require one to fix a specific equation of state. In a Friedmann-Robertson-Walker universe where the equation of state for the cosmological fluid is uncertain,…

General Relativity and Quantum Cosmology · Physics 2015-01-08 Matt Visser

Motivated by recent work on consistent fluid couplings in $f(R, T)$ gravity, we study cosmology in the nontrivial model $f(R, T) = R + \sigma R T$ using the Brown variational principle for a barotropic perfect fluid. For a flat FLRW…

General Relativity and Quantum Cosmology · Physics 2026-05-15 Davide Batic , Christian G. Boehmer , Denys Dutykh
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