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Related papers: Torsion gravity with non-minimally coupled fermion…

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We explore quintessence models of dark energy which exhibit non-minimal coupling between the dark matter and the dark energy components of the cosmic fluid. The kind of coupling chosen is inspired in scalar-tensor theories of gravity. We…

Astrophysics · Physics 2007-05-23 Tame Gonzalez , Genly Leon , Israel Quiros

Torsion gravity is a natural extension to Einstein gravity in the presence of the fermion matter sources. In this paper we adopt Wald's covariant method of Noether charge to construct the quasi-local energy of the Einstein-Cartan-fermion…

High Energy Physics - Theory · Physics 2017-09-06 Sheng-Lan Ko , Feng-Li Lin , Bo Ning

In this paper, we have outlined the development of an autonomous dynamical system within a general scalar-tensor gravity framework. This framework encompasses the overall structure of the non-minimally coupled scalar field functions for…

General Relativity and Quantum Cosmology · Physics 2024-10-14 S. A. Kadam , L. K. Duchaniya , B. Mishra

In this work we investigate several theoretical and phenomenological implications of a scalar -$F(R)$ gravity containing a non-minimal coupling to the scalar curvature. This kind of model is a generalization of axion-$F(R)$ gravity models,…

General Relativity and Quantum Cosmology · Physics 2020-05-20 Shin'ichi Nojiri , S. D. Odintsov , V. K. Oikonomou

We develop a non-singular bouncing cosmology using a non-trivial coupling of general relativity to fermionic fields. The usual Big Bang singularity is avoided thanks to a negative energy density contribution from the fermions. Our theory is…

General Relativity and Quantum Cosmology · Physics 2014-12-10 Stephon Alexander , Cosimo Bambi , Antonino Marciano , Leonardo Modesto

Several results related to flat Friedmann-Lema\^{\i}tre-Robertson-Walker models in the conformal (Einstein) frame of scalar-tensor gravity theories are extended. Scalar fields with arbitrary (positive) potentials and arbitrary coupling…

General Relativity and Quantum Cosmology · Physics 2014-10-14 Carlos R. Fadragas , Genly Leon

We study the coupling of fermions to Yang-Mills matrix models in the framework of emergent noncommutative gravity. It is shown that the matrix model action provides an appropriate coupling for fermions to gravity, albeit with a non-standard…

High Energy Physics - Theory · Physics 2010-02-16 Daniela Klammer , Harold Steinacker

We generalize the scalar tensor bigravity models to the non-minimal kinetic coupling scalar tensor bigravity models with two scalar fields whose kinetic terms are non-minimally coupled to two Einstein tensors constructed by two metrics. We…

General Relativity and Quantum Cosmology · Physics 2015-08-06 F. Darabi , M. Mousavi

We consider a generalized Einstein-Cartan theory, in which we add the unique covariant dimension four operators to general relativity that couples fermionic spin current to the torsion tensor (with an arbitrary strength). Since torsion is…

General Relativity and Quantum Cosmology · Physics 2017-11-01 Stefano Lucat , Tomislav Prokopec

We investigate torsion-driven cosmological dynamics within the framework of Einstein-Cartan gravity using the De Donder-Weyl Hamiltonian formalism, where the tetrad and Lorentz connection act as independent variables and the Hamiltonian…

General Relativity and Quantum Cosmology · Physics 2026-02-18 Aarav Shah , M. Yu. Khlopov , M. Krasnov

A formulation of cosmology driven by fermions $\psi $ is studied. Assumption that the expectation value of the fermion bilinear is non-zero simplifies the homogeneous solution of the Dirac equations and connects the spinor field with the…

General Relativity and Quantum Cosmology · Physics 2023-06-09 David Benisty

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 develop a semiclassical theory of modified gravity with nontrivial spacetime torsion. In particular, we show that the semiclassical treatment can be axiomatized in the case of Einstein--Cartan theory with a nonminimally coupled, free…

General Relativity and Quantum Cosmology · Physics 2026-02-26 R. Morales-Cabrera , Y. Bonder

In this work we consider gravitational theories in which the effect of coupling characteristic classes, appropriately introduced as operators in the Einstein-Hilbert action, has been taken into account. As it is well known, this approach…

General Relativity and Quantum Cosmology · Physics 2016-07-29 J. Lorca Espiro , Yerko Vásquez

In the framework of teleparallel gravity, the Friedman-Robertson-Walker cosmological model with scalar tensor theory where scalar field is non-minimally coupled to both the torsion scalar and boundary term is studied. Utilizing the Noether…

General Relativity and Quantum Cosmology · Physics 2018-08-29 Ganim Gecim , Yusuf Kucukakca

We discuss, in the context of alternative theories of gravity with nonminimal coupling between matter and curvature, if inflationary solutions driven by a single scalar field can be reconciled with the swampland conjectures about the…

General Relativity and Quantum Cosmology · Physics 2023-04-19 Orfeu Bertolami , Cláudio Gomes , Paulo M. Sá

In this contribution one examines the generalization of the $f(R)$ theories of gravity where one introduces a non-minimal coupling between curvature and matter. This model has new and interesting features. %, specially concerning the energy…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Orfeu Bertolami , Miguel Carvalho Sequeira

We study a model of scalar field with a general non-minimal kinetic coupling to itself and to the curvature. The cosmological dynamics of this model and the issue of accelerated expansion is analyzed. Solutions giving rise to power law…

High Energy Physics - Theory · Physics 2011-01-17 L. N. Granda

The non-Abelian Kaluza-Klein unification of gravitation with gauge fields theory is reformulated, with the inclusion of a massive spin-2 field defined by the extrinsic curvature. The internal space is non-compact, characterized by the group…

High Energy Physics - Theory · Physics 2013-11-01 D. C. N. Cunha , M. D. Maia

We consider cosmological dynamics in the theory of gravity with the scalar field possessing the nonminimal kinetic coupling to curvature given as $\kappa G^{\mu\nu}\phi_{,\mu}\phi_{,\nu}$, and the Higgs-like potential…

General Relativity and Quantum Cosmology · Physics 2017-09-18 Jiro Matsumoto , Sergey V. Sushkov