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Related papers: A Primer on Energy Conditions

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Wormholes are hypothetical shortcuts in spacetime that in General Relativity unavoidably violate all of the pointwise energy conditions. In this paper, we consider several wormhole spacetimes that, as opposed to the standard \emph{designer}…

General Relativity and Quantum Cosmology · Physics 2017-12-19 Cecilia Bejarano , Francisco S. N. Lobo , Gonzalo J. Olmo , Diego Rubiera-Garcia

It is shown that the averaged null energy condition is fulfilled for a dense, translationally invariant set of vector states in any local quantum field theory in two-dimensional Minkowski spacetime whenever the theory has a mass gap and…

Mathematical Physics · Physics 2015-06-26 Rainer Verch

For theories of relativistic matter fields there exist two possible definitions of the stress-energy tensor, one defined by a variation of the action with the coframes at fixed connection, and the other at fixed torsion. These two…

High Energy Physics - Theory · Physics 2017-07-19 Michael Geracie , Kartik Prabhu , Matthew M. Roberts

Recently, Avik De and L.T. How claim that we have not followed an effective theory approach for $f(Q)$ gravity, missing relevant terms to compute the energy conditions [Phys. Rev. D 102, 024057 (2020)]. They also state that we did not…

General Relativity and Quantum Cosmology · Physics 2022-08-30 Sanjay Mandal , P. K. Sahoo , J. R. L. Santos

Recent discoveries in the field of observational cosmology have provided increasing evidence that the Universe is undergoing a late time acceleration, which has also stimulated speculations on the nature of the dark component responsible…

Astrophysics · Physics 2009-11-10 J. Santos , J. S. Alcaniz

We examine the validity of classical energy conditions in nonsingular bouncing cosmological solutions arising in quadratic curvature gravity minimally coupled to a scalar field. Focusing on the null, weak, strong, and dominant energy…

General Relativity and Quantum Cosmology · Physics 2026-04-30 Yuki Hashimoto , Kazuharu Bamba , Sanjay Mandal

The attempt to describe the recent accelerated expansion of the Universe includes different propositions for dark energy models and modified gravity theories. Establish their features in order to discriminate and even rule out part of these…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-01 M. Penna-Lima , S. D. P. Vitenti , M. E. S. Alves , J. C. N. de Araujo , F. C. Carvalho

This paper is devoted to study the energy conditions in F(R,T) gravity for FRW universe with perfect fluid, where $R$ is the Ricci scalar and $T$ is the torsion scalar. We construct the general energy conditions in this theory and reduce…

General Relativity and Quantum Cosmology · Physics 2013-10-23 M. Sharif , S. Rani , R. Myrzakulov

Recently, a de-Sitter epoch has been found in the new model of loop quantum cosmology which is governed by the scalar constraint with both of Euclidean and Lorentz terms. The singularity free bounce in the new LQC model and the emergent…

General Relativity and Quantum Cosmology · Physics 2021-08-30 Gaoping Long , Yunlong Liu , Xiangdong Zhang

We present and discuss the bounds from the energy conditions on a general f(R) functional form in the framework of metric variational approach. As a concrete application of the energy conditions to locally homogeneous and isotropic…

Astrophysics · Physics 2010-09-15 J. Santos , M. J. Reboucas , J. S. Alcaniz

Traversable wormholes necessarily require violations of the averaged null energy condition; this being the definition of ``exotic matter''. However, the theorems which guarantee the energy condition violation are remarkably silent when it…

General Relativity and Quantum Cosmology · Physics 2011-07-18 Matt Visser , Sayan Kar , Naresh Dadhich

In this paper, we review modified $f(R)$ theories of gravity in Palatini formalism. In this framework, , we use the Raychaudhuri's equation along with the requirement that the gravity is attractive, which holds for any geometrical theory of…

General Relativity and Quantum Cosmology · Physics 2021-03-02 H. Saiedi

We study the Energy Conditions in modified $f(G)$ gravity, with $G$ being the topological Gauss-Bonnet term. Then we use the cosmographic parameters to constrain the functional form of the gravitational action and investigate the…

General Relativity and Quantum Cosmology · Physics 2026-03-18 Francesco Bajardi

We consider the problem of energy for spinor fields coupled to their surrounding curved-twisted space-time, and we show that when treated geometrically we cannot even be certain that there is a problem for the energy in the first place.

General Relativity and Quantum Cosmology · Physics 2018-01-04 Luca Fabbri

We consider the familiar junction conditions described by Israel for thin timelike walls in Einstein-Hilbert gravity. One such condition requires the induced metric to be continuous across the wall. Now, there are many spacetimes with…

General Relativity and Quantum Cosmology · Physics 2010-05-12 Donald Marolf , Sho Yaida

In physical theories, boundary or initial conditions play the role of selecting special situations which can be described by a theory with its general laws. Cosmology has long been suspected to be different in that its fundamental theory…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Martin Bojowald

The time energy uncertainty relation has been a controversial issue since the advent of quantum theory, with respect to appropriate formalisation, validity and possible meanings. A comprehensive account of the development of this subject up…

Quantum Physics · Physics 2022-09-21 P. Busch

The article describes a new approach to obtaining the energy-momentum tensor of electromagnetic field in medium without the use of Maxwell's equations and Poynting theorem. The energy-momentum tensor has new qualities and consequences. Its…

Classical Physics · Physics 2017-04-13 Yurii A. Spirichev

We give a derivation of the Einstein equation for gravity which employs a definition of the local energy density of the gravitational field as a symmetric second rank tensor whose value for each observer gives the trace of the spatial part…

Mathematical Physics · Physics 2008-03-13 Maurice J. Dupre

Violation of the null energy condition plays an important role both in the general theory of relativity and quantum field theory in curved spacetimes. Over the years, it has been shown that the violation of the null energy condition leads…

General Relativity and Quantum Cosmology · Physics 2021-09-14 Susobhan Mandal
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