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Related papers: Noncommutative Scalar Field Coupled to Gravity

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Non-minimally coupling a scalar field to gravity introduces an additional curvature term into the action which can change the general behavior in strong curvature regimes, in particular close to classical singularities. While one can…

General Relativity and Quantum Cosmology · Physics 2014-11-17 M. Bojowald , M. Kagan

The effects of a scalar field, known as the "assistant field," which nonminimally couples to gravity, on single-field inflationary models are studied. The analysis provides analytical expressions for inflationary observables such as the…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-31 Sang Chul Hyun , Jinsu Kim , Tatsuki Kodama , Seong Chan Park , Tomo Takahashi

In this study, we investigate swampland conjectures within the setup of matter and non-metricity nonminimal coupling theories of gravity. We examine how the inflationary solution produced by a single scalar field can be resolved with the…

General Relativity and Quantum Cosmology · Physics 2024-01-01 Sanjay Mandal , Kazuharu Bamba

Motivated by the Higgs Inflation scenario, we study static spherically-symmetric solutions of the non-Abelian Higgs model coupled non-minimally to Gravity. We find solutions for the self-gravitating sphaleron as well as monopole-like…

General Relativity and Quantum Cosmology · Physics 2015-03-18 Y. Brihaye , Y. Verbin

We explore dynamics of cosmological models with a nonminimally coupled scalar field evolving on a spatially flat Friedmann-Lemaitre-Robertson-Walker background. We consider cosmological models including the Hilbert-Einstein curvature term…

General Relativity and Quantum Cosmology · Physics 2014-10-01 Maria A. Skugoreva , Alexey V. Toporensky , Sergey Yu. Vernov

In the framework of teleparallel equivalent of general relativity, we study a gravity theory where a scalar field beyond its minimal coupling, is also coupled with the vector torsion through a non-minimal derivative coupling. After a…

General Relativity and Quantum Cosmology · Physics 2016-12-14 Behnaz Fazlpour

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

The coupling of gravity to a scalar field raises a number of interesting questions of principle since the usual minimal coupling obtained by replacing ordinary derivatives with covariant derivatives is not available -- they are the same…

General Relativity and Quantum Cosmology · Physics 2011-10-26 Y. N. Srivastava , J. Swain , A. Widom

We show that $R^2$ gravity coupled conformally to scalar fields is equivalent to the real bosonic sector of SU(N,1)/SU(N)$\times$U(1) no-scale supergravity, where the conformal factor can be identified with the K\"ahler potential, and we…

High Energy Physics - Theory · Physics 2018-03-07 John Ellis , Dimitri V. Nanopoulos , Keith A. Olive

We present a novel derivation of scalar cosmological perturbations in the scalar-tensor extension of non-metricity gravity, where the non-metricity scalar $Q$ is non-minimally coupled to a dynamical scalar field. While previous…

General Relativity and Quantum Cosmology · Physics 2025-12-09 Ganesh Subramaniam , Avik De , Jackson Levi Said

Chaos in Robertson-Walker cosmological models where gravity is coupled to one or more scalar fields has been studied by a few authors, mostly using numerical simulations. In this paper we begin a systematic study of the analytical aspect.…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Luca Bombelli , Fernando C. Lombardo , Mario Castagnino

A new class of gravity-matter model defined with an independent non-Riemannian volume form is studied, in the second order formalism. The action has a global scale invariance symmetry, which can be broken by the equation of motion of the…

General Relativity and Quantum Cosmology · Physics 2019-05-22 David Benisty , Eduardo I. Guendelman

We investigate the cosmological dynamics of a homogeneous scalar field non-minimally coupled to torsion gravity, which also interacts with cold dark matter through energy and momentum transfer. The matter and radiation perfect fluids are…

General Relativity and Quantum Cosmology · Physics 2025-02-05 Carlos Rodriguez-Benites , Manuel Gonzalez-Espinoza , Giovanni Otalora , Manuel Alva-Morales

We derive slow-roll conditions for a scalar field which is non-minimally coupled with gravity in a consistent manner and express spectral indices of scalar/tensor perturbations in terms of the slow-roll parameters. The conformal invariance…

Astrophysics · Physics 2011-07-13 Takeshi Chiba , Masahide Yamaguchi

We obtain the leading order interaction between the graviton and the neutral scalar boson in the context of noncommutative field theory. Our approach makes use of the Ward identity associated with the invariance under a subgroup of…

High Energy Physics - Theory · Physics 2008-11-26 F. T. Brandt , M. R. Elias-Filho

We show how we can implement chaotic inflation in the context of supergravity by conveniently selecting the functional form of a strong enough non-minimal coupling between the inflaton and the Ricci scalar curvature. The procedure can be…

High Energy Physics - Phenomenology · Physics 2014-12-12 C. Pallis

We investigate effects of noncommutativity of phase space generated by two scalar fields conformally coupled to curvature in FRW cosmology. We restrict deformation of minisuperspace to noncommutativity between scalar fields and between…

General Relativity and Quantum Cosmology · Physics 2010-11-30 Behrooz Malekolkalami , Mehrdad Farhoudi

In any realistic particle physics model of inflation, the inflaton can be expected to couple to other fields. We consider a model with a dilaton-like coupling between a U(1) gauge field and a scalar inflaton. We show that this coupling can…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Neil Barnaby , Ryo Namba , Marco Peloso

We extend our analysis for scalar fields in a Robertson-Walker metric to the electromagnetic field and Dirac fields by the method of invariants. The issue of the relation between conformal properties and particle production is re-examined…

General Relativity and Quantum Cosmology · Physics 2008-11-26 F. Finelli , A. Gruppuso , G. Venturi

We consider a scalar field coupled to massless fermions through Yukawa couplings, such as the Higgs field, in a Robertson-Walker spacetime. We compute the nonlocal quantum effective action as a functional of the background scalar field and…

High Energy Physics - Theory · Physics 2022-11-29 André Benevides , Atish Dabholkar