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Related papers: Non-minimal Energy-momentum squared gravity

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We show that in modified $f(R)$ type gravity models with non-minimal coupling between matter and geometry, both the matter Lagrangian, and the energy-momentum tensor, are completely and uniquely determined by the form of the coupling. This…

General Relativity and Quantum Cosmology · Physics 2010-05-27 T. Harko

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 attempt to construct a gravitational coupling by pre-selecting an energy-momentum tensor as the source for gravitational field. The energy-momentum tensor we take is a recently derived new expression motivated by joint localization of…

General Relativity and Quantum Cosmology · Physics 2017-02-10 Tao Lei , Zi-Wei Chen , Zhen-Lai Wang , Xiang-Song Chen

Motivated by a special consideration in quantum measurement, we present a new improved energy-momentum tensor. The new tensor differs from the traditional canonical and symmetric ones, and can be derived as Nother current from a Lagrangian…

General Relativity and Quantum Cosmology · Physics 2019-03-06 Tao Lei , Zi-Wei Chen , Zhen-Lai Wang , Xiang-Song Chen*

We consider an extension of standard General Relativity in which the Hilbert-Einstein action is replaced by an arbitrary function of the Ricci scalar, nonmetricity, torsion, and the trace of the matter energy-momentum tensor. By…

General Relativity and Quantum Cosmology · Physics 2024-11-18 Tiberiu Harko , Nurgissa Myrzakulov , Ratbay Myrzakulov , Shahab Shahidi

We consider modified theories of gravity with a direct coupling between matter and geometry, denoted by an arbitrary function in terms of the Ricci scalar. Due to such a coupling, the matter stress tensor is no longer conserved and there is…

General Relativity and Quantum Cosmology · Physics 2015-06-05 Yousef Bisabr

We establish a new self-consistent system of equations for the gravitational and electromagnetic fields. The procedure is based on a non-minimal non-linear extension of the standard Einstein-Hilbert-Maxwell action. General properties of a…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Alexander B. Balakin , José P. S. Lemos

We construct an extension of f(T) gravity with the inclusion of a non-minimal torsion-matter coupling in the action. The resulting theory is a novel gravitational modification, since it is different from both f(T) gravity, as well as from…

General Relativity and Quantum Cosmology · Physics 2014-07-01 Tiberiu Harko , Francisco S. N. Lobo , G. Otalora , Emmanuel N. Saridakis

In this paper we have revisited the energy-momentum squared gravity theory, by taking into account the second derivative of the matter Lagrangian with respect to the metric, encapsulating relations originated from thermodynamical grounds.…

General Relativity and Quantum Cosmology · Physics 2026-02-02 Mihai Marciu

Recently, in the context of f(R) modified theories of gravity, it was shown that a curvature-matter coupling induces a non-vanishing covariant derivative of the energy-momentum, implying non-geodesic motion and, under appropriate…

General Relativity and Quantum Cosmology · Physics 2008-11-19 Orfeu Bertolami , Tiberiu Harko , Francisco S. N. Lobo , Jorge Páramos

In this proceeding, we review modified theories of gravity with a curvature-matter coupling between an arbitrary function of the scalar curvature and the Lagrangian density of matter. This explicit nonminimal coupling induces a…

General Relativity and Quantum Cosmology · Physics 2022-09-20 Francisco S. N. Lobo , Tiberiu Harko

We present a novel theory of gravity by considering an extension of symmetric teleparallel gravity. This is done by introducing, in the framework of the metric-affine formalism, a new class of theories where the nonmetricity $Q$ is…

General Relativity and Quantum Cosmology · Physics 2018-10-31 Tiberiu Harko , Tomi S. Koivisto , Francisco S. N. Lobo , Gonzalo J. Olmo , Diego Rubiera-Garcia

We study the properties of the energy-momentum tensor in non-commutative gauge theories by coupling them to a weak external gravitational field. In particular, we show that the stress tensor of such a theory coincides exactly with that…

High Energy Physics - Theory · Physics 2008-11-26 Ashok Das , J. Frenkel

We provide a field-theoretic algorithm of obtaining energy momentum tensor (EMT) for gravitationally coupled theories. The method is based on an auxiliary field theory and equally applicable to both minimal and non-minimal coupling. The…

General Relativity and Quantum Cosmology · Physics 2018-03-08 Pradip Mukherjee , Anirban Saha , Amit Singha Roy

We investigate some cosmological models arising from a non-minimal coupling of a fermionic field to gravity in the geometrical setting of Einstein-Cartan-Sciama-Kibble gravity. The role played by the non-minimal coupling together with…

General Relativity and Quantum Cosmology · Physics 2015-03-05 Stefano Vignolo , Sante Carloni , Luca Fabbri

We present a novel theory of gravity, namely, an extension of symmetric teleparallel gravity. This is done by introducing a new class of theories where the nonmetricity $Q$ is coupled nonminimally to the matter Lagrangian. This nonminimal…

General Relativity and Quantum Cosmology · Physics 2019-01-04 Francisco S. N. Lobo , Tiberiu Harko , Tomi S. Koivisto , Gonzalo J. Olmo , Diego Rubiera-Garcia

Theories with a non-minimal coupling between the space-time curvature and matter fields introduce an extra force due to the non-conservation of the matter energy momentum. In the present work the theoretical consistency of such couplings is…

General Relativity and Quantum Cosmology · Physics 2013-10-02 Nicola Tamanini , Tomi S. Koivisto

We propose a phenomenological model in which a non-minimal coupling between gravity and dark matter is present in order to address some of the apparent small scales issues of \lcdm model. When described in a frame in which gravity dynamics…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-24 Dario Bettoni , Valeria Pettorino , Stefano Liberati , Carlo Baccigalupi

We study a theory which generalizes the nonminimal coupling of matter to gravity by including derivative couplings. This leads to several interesting new dynamical phenomena in cosmology. In particular, the range of parameters in which…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Luca Amendola

We investigate the consequences of non-minimal gravitational coupling to matter and study how it differs from the case of minimal coupling by choosing certain simple forms for the nature of coupling, The values of the parameters are…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-03 Shruti Thakur , Anjan A Sen , T. R. Seshadri
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