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We generalize and unify the $f(R,T)$ and $f(R,L_m)$ type gravity models by assuming that the gravitational Lagrangian is given by an arbitrary function of the Ricci scalar $R$, of the trace of the energy-momentum tensor $T$, and of the…

General Relativity and Quantum Cosmology · Physics 2021-07-28 Zahra Haghani , Tiberiu Harko

In this work, we propose different models of extended theories of gravity, which are minimally coupled to the SM fields, to explain the possibility of a dark matter (DM) candidate, without ad-hoc additions to the Standard Model (SM). We…

High Energy Physics - Theory · Physics 2016-11-28 Sayantan Choudhury , Manibrata Sen , Soumya Sadhukhan

Within the general framework of $f(R)$ gravity, we introduce a function of the electromagnetic curvature invariant $f(\mathbb{F})$ that couples minimally to gravitation to ensure a consistent treatment of curvature functions in these…

General Relativity and Quantum Cosmology · Physics 2026-03-19 Francesco Bajardi , Micol Benetti , Salvatore Capozziello , Abedennour Dib

We study the self-compactification of extra dimensions via higher curvature gravity, f(R), where f(R) is the generic function of the Ricci scalar R. First, we reduce pure f(R) theory to a scalar-tensor theory by a conformal transformation.…

High Energy Physics - Theory · Physics 2011-02-16 Beyhan Pulice , Sukru Hanif Tanyildizi

f(R)-theories of gravity are reviewed in the framework of the matter-antimatter asymmetry in the Universe. The asymmetry is generated by the gravitational coupling of heavy (Majorana) neutrinos with the Ricci scalar curvature. In order that…

High Energy Physics - Phenomenology · Physics 2015-06-23 G. Lambiase , S. Mohanty , L. Pizza

The $f(R,T)$ gravity is an extended theory of gravity in which the gravitational action contains general terms of both the Ricci scalar $R$ and trace of the energy-momentum tensor $T$. In this way, $f(R,T)$ models are capable of describing…

General Relativity and Quantum Cosmology · Physics 2017-07-20 P. H. R. S. Moraes , P. K. Sahoo

Modified theories of gravity have recently been studied by several authors as possibly viable alternatives to the cosmological concordance model. Such theories attempt to explain the accelerating expansion of the universe by changing the…

Astrophysics · Physics 2013-05-29 T. Multamaki , I. Vilja

We study inflation and late-time acceleration in the expansion of the universe in non-minimal electromagnetism, in which the electromagnetic field couples to the scalar curvature function. It is shown that power-law inflation can be…

Astrophysics · Physics 2009-06-23 Kazuharu Bamba , Sergei D. Odintsov

Late time cosmic acceleration may be achieved by modifying gravity on large scales. This should also have consequences on the evolution of perturbations. We thus extend our study of exponential infrared $f(T)$ teleparallel gravity to…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-11 Mahmoud Hashim , Amr A. El-Zant , Waleed El Hanafy , Alexey Golovnev

Whereas the nature of dark components in the Universe remains unknown, alternative models of gravity have been developed to offer a geometric explanation to the origin of such components. In this work we use the Minimal Geometric…

General Relativity and Quantum Cosmology · Physics 2020-04-03 Francisco X. Linares Cedeño , Ernesto Contreras

In this paper we discuss a class of models that address the issue of explaining the gravitational dynamics at the galactic scale starting from a geometric point of view. Instead of claiming the existence of some hidden coupling between dark…

General Relativity and Quantum Cosmology · Physics 2011-11-10 Dario Bettoni , Stefano Liberati , Lorenzo Sindoni

We investigate FLRW cosmology in the framework of symmetric teleparallel $f(Q)$ gravity with a nonminimal coupling between dark matter and the gravitational field. In the noncoincidence gauge, the field equations admit an equivalent…

General Relativity and Quantum Cosmology · Physics 2026-03-26 A. Abebe , P. S. Apostolopoulos , A. Giacomini , G. Leon , F. Moncada , A. Paliathanasis

Accurate predictions for the non-linear matter power spectrum are needed to confront theory with observations in current and near future weak lensing and galaxy clustering surveys. We propose a computationally cheap method to create an…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-01 Hans Winther , Santiago Casas , Marco Baldi , Kazuya Koyama , Baojiu Li , Lucas Lombriser , Gong-Bo Zhao

The coupling of the electromagnetic field to gravity is an age-old problem. Presently, there is a resurgence of interest in it, mainly for two reasons: (i) Experimental investigations are under way with ever increasing precision, be it in…

General Relativity and Quantum Cosmology · Physics 2016-12-07 Friedrich W. Hehl , Yuri N. Obukhov

In absence of matter Einstein gravity with a cosmological constant $\La$ can be formulated as a scale-free theory depending only on the dimensionless coupling constant G \Lambda where G is Newton constant. We derive the conformal field…

High Energy Physics - Theory · Physics 2009-11-11 Mariano Cadoni

We establish a well-posedness theory for the f(R) theory of modified gravity, which is a generalization of Einstein's theory of gravitation. The scalar curvature R of the spacetime, which arises in the integrand of the Einstein-Hilbert…

Analysis of PDEs · Mathematics 2014-12-30 Philippe G. LeFloch , Yue Ma

New corrections to General Relativity are considered in the context of modified $f(R)$ gravity, that satisfy cosmological and local gravity constraints. The proposed models behave asymptotically as $R-2\Lambda$ at large curvature and show…

General Relativity and Quantum Cosmology · Physics 2022-01-13 L. N. Granda

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 this work we study how nonminimally coupled theories of gravity modify the usual Friedmann equation, and develop two methods to treat these. The ambiguity in the form of the Lagrangian density of a perfect fluid is emphasized, and the…

General Relativity and Quantum Cosmology · Physics 2015-06-18 Orfeu Bertolami , Jorge Páramos

We study inflationary cosmology and the late-time accelerated expansion of the universe in non-minimal Yang-Mills (YM) theory, in which the YM field couples to a function of the scalar curvature. It is shown that power-law inflation can be…

High Energy Physics - Theory · Physics 2008-11-26 Kazuharu Bamba , Shin'ichi Nojiri , Sergei D. Odintsov
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