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Related papers: Perturbations in Matter Bounce with Non-minimal Co…

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We study the phenomenology associated to non-minimally coupled dark matter. In particular, we consider the model where the non-minimal coupling arises from the formation of relativistic Bose-Einstein condensates in high density regions of…

General Relativity and Quantum Cosmology · Physics 2020-08-05 Dimitar Ivanov , Stefano Liberati

After the recent GW170817 event of the two neutron stars merging, many string corrected cosmological theories confronted the non-viability peril. This was due to the fact that most of these theories produce massive gravitons primordially.…

General Relativity and Quantum Cosmology · Physics 2021-02-03 V. K. Oikonomou , F. P. Fronimos

We consider perturbations in the isotropic and homogeneous cosmological model with the spatially flat Friedmann-Lemaitre-Robertson-Walker metric in the framework of the theory of gravity with non-minimal derivative coupling. The Lagrangian…

General Relativity and Quantum Cosmology · Physics 2026-05-14 R. I. Kamalitdinov , S. V. Sushkov

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

The matter bounce scenario allows for a sizable parameter space where cosmological fluctuations originally exited the Hubble radius when the background energy density was small. In this scenario and its extended versions, the low energy…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-02 Yi-Fu Cai , Francis Duplessis , Damien A. Easson , Dong-Gang Wang

Realistic models of particle physics include many scalar fields. These fields generically have nonminimal couplings to the Ricci curvature scalar, either as part of a generalized Einstein theory or as necessary counterterms for…

Cosmology and Nongalactic Astrophysics · Physics 2010-09-27 David I. Kaiser , Audrey T. Todhunter

In this work, one examines how the presence of a non-minimal coupling between the spacetime curvature and matter affects the evolution of cosmological perturbations around a homogeneous and isotropic Universe and hence the formation of…

General Relativity and Quantum Cosmology · Physics 2013-05-27 Orfeu Bertolami , Pedro Frazão , Jorge Páramos

In extended models of gravity a nonminimal coupling to matter has been assumed to lead to irreversible particle creation. In this paper we challenge this assumption. We argue that a non-minimal coupling of the matter and gravitational…

General Relativity and Quantum Cosmology · Physics 2019-04-02 R. P. L. Azevedo , P. P. Avelino

It has been shown that primordial tensor non-Gaussianities from a cubic Weyl action with a non-dynamical coupling are suppressed by the so-called slow-roll parameter in a conventional framework of slow-roll inflation. In this paper, we…

General Relativity and Quantum Cosmology · Physics 2024-09-18 Shingo Akama , Mian Zhu

It was recently realized that a model constructed from a Lee-Wick type scalar field theory yields, at the level of homogeneous and isotropic background cosmology, a bouncing cosmology. However, bouncing cosmologies induced by pressure-less…

High Energy Physics - Theory · Physics 2013-05-29 Johanna Karouby , Taotao Qiu , Robert Brandenberger

We explore a cosmological model in which dark matter is non-minimally coupled to gravity at the fluid level. While typically subdominant compared to Standard Model forces, such couplings may dominate dark matter dynamics. We show that this…

General Relativity and Quantum Cosmology · Physics 2025-10-14 Samuele Silveravalle , Andrea Lapi , Francesco Benetti , Stefano Liberati

We study inflationary scenarios driven by a scalar field in the presence of a non-minimal coupling between matter and curvature. We show that the Friedmann equation can be significantly modified when the energy density during inflation…

General Relativity and Quantum Cosmology · Physics 2017-06-28 Cláudio Gomes , João G. Rosa , Orfeu Bertolami

In this work, we review a plethora of modified theories of gravity with generalized curvature-matter couplings. The explicit nonminimal couplings, for instance, between an arbitrary function of the scalar curvature $R$ and the Lagrangian…

General Relativity and Quantum Cosmology · Physics 2014-07-29 Tiberiu Harko , Francisco S. N. Lobo

The evolution of density perturbations is analysed in a modified theory of gravity with a nonminimal coupling between curvature and matter. We consider the broken degeneracy between the choices of matter Lagrangian for a perfect fluid,…

General Relativity and Quantum Cosmology · Physics 2026-01-26 Miguel Barroso Varela , Orfeu Bertolami

Gravitational waves in the presence of a non-minimal curvature-matter coupling are analysed, both in the Newman-Penrose and perturbation theory formalisms. Considering a cosmological constant as a source, the non-minimally coupled…

General Relativity and Quantum Cosmology · Physics 2018-05-03 Orfeu Bertolami , Cláudio Gomes , Francisco S. N. Lobo

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 extend the phenomenology of loop quantum cosmology (LQC) to second order in perturbations. Our motivation is twofold. On the one hand, since LQC predicts a cosmic bounce that takes place at the Planck scale, the second order…

General Relativity and Quantum Cosmology · Physics 2018-04-04 Ivan Agullo , Boris Bolliet , V. Sreenath

We examine an extension of General Relativity with an explicit non-minimal coupling between matter and curvature. The purpose of this work is to present an overview of the implications of the latter to various contexts, ranging from…

General Relativity and Quantum Cosmology · Physics 2014-01-20 Orfeu Bertolami , Jorge Páramos

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

One of the most interesting and current phenomenological extensions of General Relativity is the so-called $f (R)$ class of theories; a natural generalization of this includes an explicit non-minimal coupling between matter and curvature.…

General Relativity and Quantum Cosmology · Physics 2011-11-16 J. Páramos
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