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We explore the viable $f(R)$ gravity models in FLRW backgrounds with a free spatial curvature parameter $\Omega_{K}$. In our numerical calculation, we concentrate on the exponential $f(R)$ model of $f(R) = R - \lambda…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-18 Chao-Qiang Geng , Yan-Ting Hsu , Jhih-Rong Lu

In this {\sl Letter} we construct the Hubble diagram (HD) for the standard Friedmann-Lema\^itre-Robertson-Walker (FLRW) cosmological model after enforcing it with the general relativistic energy conditions, heeding to investigate whether it…

It is shown that the Cotton tensor can describe the effects of gravity beyond general relativity. Any solution of the Einstein equations with or without the cosmological constant satisfies the field equations described by the Cotton tensor.…

General Relativity and Quantum Cosmology · Physics 2021-06-23 Junpei Harada

We construct a compact phase space for flat FLRW spacetimes with standard matter described by a perfect fluid with a barotropic equation of state for general f(R) theories of gravity, subject to certain conditions on the function f. We then…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Mohamed Abdelwahab , Rituparno Goswami , Peter K. S. Dunsby

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

We propose a new method for obtaining an effective Friedmann-Lema\^itre-Robertson-Walker (FLRW) cosmology from the quantum gravity dynamics of group field theory (GFT), based on the idea that an FLRW universe is characterised by a few…

General Relativity and Quantum Cosmology · Physics 2022-03-10 Steffen Gielen , Luca Marchetti , Daniele Oriti , Axel Polaczek

Recently, it was formulated a teleparallel theory called $f(T,B)$ gravity which connects both $f(T)$ and $f(R)$ under suitable limits. In this theory, the function in the action is assumed to depend on the torsion scalar $T$ and also on a…

General Relativity and Quantum Cosmology · Physics 2017-12-19 Sebastian Bahamonde , M. Zubair , G. Abbas

An effective Lagrangian approach, partly inspired by Quantum Loop Cosmology (QLC), is presented and formulated in a non flat FLRW space-times, making use of modified gravitational models. The models considered are non generic, and their…

General Relativity and Quantum Cosmology · Physics 2020-05-15 Alessandro Casalino , Lorenzo Sebastiani , Luciano Vanzo , Sergio Zerbini

The homogeneous Friedman-Lema\^\i tre-Robertson-Walker (FLRW) cosmology of a free scalar field with vanishing cosmological constant was recently shown to be invariant under the one-dimensional conformal group $\textrm{SL}(2,\mathbb{R})$…

General Relativity and Quantum Cosmology · Physics 2020-09-17 Jibril Ben Achour , Etera R. Livine

We investigate the modified gravity in which the Lagrangian of gravity is a function of the trace of the n-th matrix power of Ricci tensor in a Friedmann-Lemaitre-Robertson-Walker(FLRW) spacetime. When n is negative, the inverse of Ricci…

General Relativity and Quantum Cosmology · Physics 2025-01-29 Yicen Mou

We construct a cosmological model from the inception of the Friedmann-Lem\^aitre-Robertson-Walker metric into the field equations of the f(R,L_m) gravity theory, with R being the Ricci scalar and L_m being the matter lagrangian density. The…

General Relativity and Quantum Cosmology · Physics 2024-03-21 B. S. Gonçalves , P. H. R. S. Moraes , B. Mishra

Recently it has been noted by Di Valentino, Melchiorri and Silk (2019) that the enhanced lensing signal relative to that expected in the spatially flat $\Lambda$CDM model poses a possible crisis for the…

General Relativity and Quantum Cosmology · Physics 2020-08-12 Asta Heinesen , Thomas Buchert

We revisit spatially flat FLRW cosmology in light of recent advances in standard model relativistic fluid dynamics. Modern fluid dynamics requires the presence of curvature-matter terms in the energy-momentum tensor for consistency. These…

General Relativity and Quantum Cosmology · Physics 2019-07-09 Rudolf Baier , Sayantani Lahiri , Paul Romatschke

We study a Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) space-time in the theory of $f(Q)$-gravity, where $Q$ denotes the non-metricity scalar. It has been previously shown in the literature, that there exist four distinct families of…

General Relativity and Quantum Cosmology · Physics 2022-08-17 N. Dimakis , A. Paliathanasis , M. Roumeliotis , T. Christodoulakis

We provide a new extension of general relativity (GR) which has the remarkable property of being more constrained than GR plus a cosmological constant, having one less free parameter. This is implemented by allowing the cosmological…

General Relativity and Quantum Cosmology · Physics 2019-10-09 Stephon Alexander , Marina Cortês , Andrew R. Liddle , João Magueijo , Robert Sims , Lee Smolin

The cosmological implications of the Covariant Canonical Gauge Theory of Gravity (CCGG) are investigated. We deduce that, in a metric compatible geometry, the requirement of covariant conservation of matter invokes torsion of space-time. In…

General Relativity and Quantum Cosmology · Physics 2024-10-28 David Vasak , Johannes Kirsch , Juergen Struckmeier

We investigate observational tests that can be used to distinguish between broad classes of cosmological models. This is achieved using curvature-consistency tests of the Friedmann-Lema\^{i}tre-Robertson-Walker (FLRW) models, which we…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-09 Asta Heinesen , Timothy Clifton

We consider the symmetric teleparallel $f\left( Q\right) $-gravity in Friedmann--Lema\^{\i}tre--Robertson--Walker cosmology with nonzero spatial curvature. For a nonlinear $f\left( Q\right) $ model there exist always the limit of General\…

General Relativity and Quantum Cosmology · Physics 2023-10-09 Andronikos Paliathanasis

The dynamics of perfect fluid as a source in the context of modified gravity, specifically $f(Q,T)$ gravity, are examined within the Friedmann-Lema\^itre-Robertson-Walker (FLRW) cosmological model. This gravity is a generic function of the…

General Relativity and Quantum Cosmology · Physics 2024-08-02 S. H. Shekh , Anirudh Pradhan , S. P. Gaikwad , K. R. Mule

We investigate a spatially flat FLRW cosmological model in the framework of modified gravity described by the function \( f(R, L_m) = \alpha R + L_m^\beta + \gamma \), where \( L_m \) is the matter Lagrangian density. The modified Friedmann…

General Relativity and Quantum Cosmology · Physics 2026-02-05 G. K. Goswami , Anirudh Pradhan , Syamala Krishnannair