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We consider a gravitational theory with an additional non-minimal coupling between baryonic matter fields and geometry. The coupling is second order in the energy momentum tensor and can be seen as a generalization of the energy-momentum…

General Relativity and Quantum Cosmology · Physics 2021-04-19 Shahab Shahidi

In this work, we propose a CPT-even and Lorentz-violating dimension-five nonminimal coupling between fermionic and gauge fields, involving the CTP-even and Lorentz-violating gauge tensor of the SME. This nonminimal coupling modifies the…

High Energy Physics - Theory · Physics 2013-04-29 R. Casana , M. M. Ferreira , E. O. Silva , E. Passos , F. E. P. dos Santos

We study a large family of metric-affine theories with a projective symmetry, including non-minimally coupled matter fields which respect this invariance. The symmetry is straightforwardly realised by imposing that the connection only…

General Relativity and Quantum Cosmology · Physics 2017-05-23 V. I. Afonso , Cecilia Bejarano , Jose Beltran Jimenez , Gonzalo J. Olmo , Emanuele Orazi

We propose a CPT-even and Lorentz-violating dimension-five nonminimal coupling between fermionic and gauge fields, involving the CPT-even and Lorentz-violating gauge tensor of the Standard-Model Extension. This nonminimal coupling modifies…

High Energy Physics - Theory · Physics 2017-08-23 R. Casana , M. M. Ferreira , E. Passos F. E. P. Dos Santos , E. O. Silva

In this work we explore the viability of nonminimally coupled matter- curvature gravity theories, namely the conditions required for the absence of tachyon instabilities and ghost degrees of freedom. We contrast our finds with recent claims…

General Relativity and Quantum Cosmology · Physics 2017-02-22 Orfeu Bertolami , Jorge Páramos

We consider a geometric approach to field theory in which torsion is present beside gravity and also electrodynamics for the matter field equations, and we develop the consequences of the torsion-spin coupling for the spinor fields; we show…

High Energy Physics - Theory · Physics 2011-10-04 Luca Fabbri

We consider a modified action functional with a non-minimum coupling between the scalar curvature and the matter Lagrangian, and study its consequences on stellar equilibrium. Particular attention is paid to the validity of the Newtonian…

Astrophysics · Physics 2009-06-23 O. Bertolami , J. Paramos

Using a generalised Noether prescription we are able to extract all the currents and their conservation laws in space dependent shift symmetric theories. Various identities among the currents in the matter sector are found that form the…

High Energy Physics - Theory · Physics 2023-09-27 Rabin Banerjee , Anwesha Chakraborty

In this paper, we consider rolling tachyon, with steep run-away type of potentials non-minimally coupled to massive neutrino matter. The coupling dynamically builds up at late times as neutrino matter turns non-relativistic. In case of…

General Relativity and Quantum Cosmology · Physics 2016-08-05 Safia Ahmad , Nurgissa Myrzakulov , R. Myrzakulov

We use the Lagrange-Noether methods to derive the conservation laws for models in which matter interacts nonminimally with the gravitational field. The nonminimal coupling function can depend arbitrarily on the gravitational field strength.…

General Relativity and Quantum Cosmology · Physics 2013-04-19 Yuri N. Obukhov , Dirk Puetzfeld

In this paper, based on the Standard Model Extended gauge sector, we made a non-minimal coupling in the Klein-Gordon equation which characterizes the Lorentz symmetry violation and, through this nonminimal CPT-odd coupling, we investigate…

High Energy Physics - Theory · Physics 2019-08-13 Ricardo L. L. Vitória , Humberto Belich

This is the first of a series of two papers where decoupling of unphysical states in the minimal pure spinor formalism is investigated. The multi-loop amplitude prescription for the minimal pure spinor superstring formulated in…

High Energy Physics - Theory · Physics 2010-01-16 Joost Hoogeveen , Kostas Skenderis

The non-minimal coupling of gravity to a scalar field can be transformed into a minimal coupling through a conformal transformation. We show how to connect the results of a perturbation calculation, performed around a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Julio C. Fabris , Joel Tossa

The non-minimal coupling of a scalar field to the Ricci curvature in a curved spacetime is unavoidable according to several authors. The coupling constant is not a free parameter: the prescriptions for the value of the coupling constant in…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Valerio Faraoni

Nontrivial translation matrices occur for spin (A,B)+(C,D) with |A-C| = |B-D| = 1/2, necessarily associating a (C,D) field with a spin (A,B) field. Including translation matrices in covariant non-unitary Poincare representations also…

High Energy Physics - Theory · Physics 2007-05-23 Richard Shurtleff

We study interactions between like charges in the noncommutative Maxwell-Chern-Simons electrodynamics {\it{minimally}} coupled to spinors or scalars. We demonstrate that the non-relativistic potential profiles, for only spatial…

High Energy Physics - Theory · Physics 2011-07-19 Subir Ghosh

Multifield models of inflation with nonminimal couplings are in excellent agreement with the recent results from {\it Planck}. Across a broad range of couplings and initial conditions, such models evolve along an effectively single-field…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-08 David I. Kaiser , Evangelos I. Sfakianakis

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 introduce a new model of spin noncommutative space in which noncommutative extension of the coordinate operators are assumed to be chirality dependent. Noncommutative correspondences of classical fields are defined via Weyl ordering, and…

High Energy Physics - Phenomenology · Physics 2019-03-28 Kai Ma

We look for possible evidence of a non-minimal coupling (NMC) between dark matter (DM) and gravity using data from the X-COP compilation of galaxy clusters. We consider a theoretically motivated NMC that may dynamically arise from the…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-26 Giovanni Gandolfi , Balakrishna Sandeep Haridasu , Stefano Liberati , Andrea Lapi