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Related papers: Energy and Angular Momentum Densities in a Godel-T…

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We present a method based on the so-called Quantum Energy Inequalities, which allows to compare, and bound, the expectation values of energy-densities of ground states of quantum fields in spacetimes possessing isometric regions. The method…

General Relativity and Quantum Cosmology · Physics 2007-05-23 P. Marecki

The present paper is elaborated to discuss the energy condition bounds in a modified teleparallel gravity namely $F(T,T_{G})$, involving torsion invariant $T$ and contribution from a term $T_G$, the teleparallel equivalent of the…

General Relativity and Quantum Cosmology · Physics 2015-09-23 Saira Waheed , M. Zubair

We determine the energy-momentum tensor of non-perfect fluids in thermodynamic equilibrium. To this end, we derive the constitutive equations for energy density, isotropic and anisotropic pressure as well as for heat-flux from the…

General Relativity and Quantum Cosmology · Physics 2016-04-26 Konrad Schatz , Horst-Heino von Borzeszkowski , Thoralf Chrobok

A simple gravitational model with torsion is studied, and it is suggested that it could explain the dark matter and dark energy in the universe. It can be reinterpreted as a model using the Einstein gravitational equations where spacetime…

General Relativity and Quantum Cosmology · Physics 2022-03-28 Graeme W. Milton

We present a general relativistic version of the self-gravitating fluid model for the dark sector of the Universe (darkon fluid) introduced in Phys. Rev. 80 (2009) 083513 and extended and reviewed in Entropy (2013) 559. This model contains…

General Relativity and Quantum Cosmology · Physics 2015-06-22 P. C. Stichel , W. J. Zakrzewski

The M$\o$ller tetrad gravitational energy-momentum expression was recently evaluated for a small vacuum region using orthonormal frames adapted to Riemann normal coordinates. However the result was not proportional to the Bel-Robinson…

General Relativity and Quantum Cosmology · Physics 2008-09-24 Lau Loi So

Nullification of the Einstein tensor curvature for the elementary material space with active gravitational field (radial source) and passive field distribution of its inertial particle (radial sink) maintains the conceptual equivalence of…

General Physics · Physics 2010-11-09 I. E. Bulyzhenkov

The gravitational energy-momentum within a small region as determined by two tetrad-teleparallel expressions is evaluated with the aid of an orthonormal frame adapted to Riemann normal coordinates. We find that the gauge current "tensor"…

General Relativity and Quantum Cosmology · Physics 2012-07-31 Lau Loi So , James M. Nester

We construct the Effective Field Theory (EFT) of the teleparallel equivalent of general relativity (TEGR). Firstly, we present the necessary field redefinitions of the scalar field and the tetrads. Then we provide all the terms at…

General Relativity and Quantum Cosmology · Physics 2023-05-12 Maria Mylova , Jackson Levi Said , Emmanuel N. Saridakis

We discuss the equation of motion of the rotating homogenous and isotropic model of the Universe. We show that the model predicts the presence of a minimum in the relation between the mass of an astronomical object and its angular momentum.…

Astrophysics · Physics 2015-06-24 Wlodzimierz Godlowski , Marek Szydlowski , Piotr Flin , Monika Biernacka

A new prescription to calculate the total energies and angular momenta of asymptotically $(d+1)$-dimensional anti-de Sitter spacetimes is proposed. The method is based on an extension of the field theoretical approach to General Relativity…

General Relativity and Quantum Cosmology · Physics 2016-08-15 N. Pinto-Neto , R. Rodrigues da Silva

Equal-time commutators of different components of the energy-momentum tensor at spatially separated points are calculated for a relativistic quantum Fermi gas at finite temperature and density. Different definitions of such components, also…

High Energy Physics - Phenomenology · Physics 2024-09-30 Sourav Dey , Samapan Bhadury , Wojciech Florkowski , Radoslaw Ryblewski , Amaresh Jaiswal

We establish a general relation between the canonical energy-momentum tensor of Lagrangian dynamics and the tensor that acts as the source of the gravitational field in Einstein's equations, and we show that there is a discrepancy between…

General Relativity and Quantum Cosmology · Physics 2013-03-01 Hans C. Ohanian

In this work a tetrad theory of gravity, invariant under conformal transformations, is investigated. The action of the theory is similar to the action of Maxwell's electromagnetism. The role of the electromagnetic gauge potential is played…

General Relativity and Quantum Cosmology · Physics 2012-06-28 J. W. Maluf , F. F. Faria

General relativistic effects in the weak field approximation are calculated for electromagnetic Laguerre-Gaussian (LG) beams. The current work is an extension of previous work on the precession of a spinning neutral particle in the weak…

General Relativity and Quantum Cosmology · Physics 2018-07-04 James Strohaber

We generalize tensor-scalar theories of gravitation by the introduction of an abnormally weighting type of energy. This theory of tensor-scalar anomalous gravity is based on a relaxation of the weak equivalence principle that is now…

Astrophysics · Physics 2009-01-14 J. -M. Alimi , A. Füzfa

We consider a gravitational model in which matter is non-minimally coupled to geometry, with the effective Lagrangian of the gravitational field being given by an arbitrary function of the Ricci scalar, the trace of the matter…

General Relativity and Quantum Cosmology · Physics 2024-11-18 Zahra Haghani , Tiberiu Harko , Francisco S. N. Lobo , Hamid Reza Sepangi , Shahab Shahidi

We generalize the $f(R)$ type gravity models by assuming that the gravitational Lagrangian is given by an arbitrary function of the Ricci scalar $R$ and of the matter Lagrangian $L_m$. We obtain the gravitational field equations in the…

General Relativity and Quantum Cosmology · Physics 2011-02-09 Tiberiu Harko , Francisco S. N. Lobo

The field equations of a special class of teleparallel theory of gravitation and electromagnetic fields have been applied to tetrad space having cylindrical symmetry with four unknown functions of radial coordinate $r$ and azimuth angle…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Gamal G. L. Nashed

This paper is devoted to investigate the recently introduced $f(\mathcal{G},\textit{T})$ theory of gravity, where $\mathcal{G}$ is the Gauss-Bonnet term, and ${\textit{T}}$ is the trace of the energy-momentum tensor. For this purpose,…

General Physics · Physics 2017-12-13 M. Farasat Shamir