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Related papers: Modified $f(Q)$ gravity models and their cosmologi…

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We reconstruct an $f(R)$ gravity model that gives rise to the particular $\Lambda$CDM background evolution of the universe. We find well-defined, real-valued analytical forms for the $f(R)$ model to describe the universe both in the early…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Jian-hua He , Bin Wang

We study how the constants $G$ and $\Lambda$ may vary in different theoretical models (general relativity with a perfect fluid, scalar cosmological models (\textquotedblleft quintessence\textquotedblright) with and without interacting…

General Relativity and Quantum Cosmology · Physics 2012-04-06 José Antonio Belinchón

Choosing a phenomenological model of $\Lambda$, viz. $\Lambda \sim \dot H$, it has been shown that this model of $\Lambda$ is equivalent to other three types of $\Lambda$, $\Lambda \sim (\dot a/a)^2$, $\Lambda \sim \ddot a/a$ and $\Lambda…

Astrophysics · Physics 2011-02-28 Utpal Mukhopadhyay , Saibal Ray

In this paper, we examine the universe's expansion in $ f(R, L_{m}) $ gravity for a particular form of $ f(R, L_{m})=\frac{R}{2}+L_{m}^{n}$. The field equations for flat FLRW metric with matter Lagrangian $ L_{m}=\rho$ are derive. Hubble…

General Relativity and Quantum Cosmology · Physics 2025-02-12 Romanshu Garg , G. P. Singh , Ashwini R Lalke , Saibal Ray

Taking into account the temperature corrections of the energy equipartition law for the bits of information that are coarse-grained on the holographic screen leads to a modification of Einstein's gravitational field equations. In the very…

General Relativity and Quantum Cosmology · Physics 2025-03-12 Kazem Rezazadeh

We look for cosmologies with a scalar field (dark energy without cosmological constant), which mimic the standard $\Lambda CDM$ cosmological model yielding exactly the same large-scale geometry described by the evolution of the Hubble…

Astrophysics · Physics 2015-05-13 V. I. Zhdanov , G. Ivashchenko

This work examines the cosmological implications of two functional forms of $f(R,T) = R + \alpha T^n$ gravity: for two different value of $n $ where $n=1$ and $n\neq 1$, and $\alpha$ and $n$ are free parameters. The modified Friedmann…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-24 Mustapha Lamaaoune

We consider the cosmology where some function f(G) of the Gauss-Bonnet term G is added to the gravitational action to account for the late-time accelerating expansion of the universe. The covariant and gauge invariant perturbation equations…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Baojiu Li , John D. Barrow , David F. Mota

A modified f(R) gravity model has been recently proposed in Phys. Rev. Lett. 102, 221101 (2009) [arXiv:0905.1941] whose cosmological behaviour is clearly distinguishable from LCDM. Contrary to previous opinions which consider that…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-29 A. de la Cruz-Dombriz , A. Dobado , A. L. Maroto

A cubic correction of $f(T)$ gravity, where $T$ is the teleparallel scalar torsion, is considered to describe gravity in spatially flat Friedmann-Robertson-Walker model. A scale factor permitting departure from inflation era has been…

General Physics · Physics 2015-11-06 G. G. L. Nashed , W. El Hanafy

Here, we peruse cosmological usage of the most promising candidates of dark energy in the framework of $f(T)$ gravity theory. We reconstruct the different $f(T)$ modifed gravity models in the spatially flat FRW universe according to…

General Relativity and Quantum Cosmology · Physics 2016-10-12 Pameli Saha , Ujjal Debnath

The aim of this paper is to find higher order geometrical corrections to the Einstein-Hilbert action that can lead to only second order equations of motion. The metric formalism is used, and static spherically symmetric and…

General Relativity and Quantum Cosmology · Physics 2015-10-28 Aimeric Colléaux , Sergio Zerbini

We use the recently released cosmic chronometer data and the latest measured value of the local Hubble parameter, combined with the latest joint light curves of Supernovae Type Ia, and Baryon Acoustic Oscillation distance measurements, in…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-09 Rafael C. Nunes , Supriya Pan , Emmanuel N. Saridakis , Everton M. C. Abreu

An approach to construct cosmological inflation models on the basis of a certain dependence of the scalar field evolution on the e-folds number is considered. The reconstruction of the model background parameters according to the kind of…

General Relativity and Quantum Cosmology · Physics 2025-12-23 Igor V. Fomin , Vladimir L. Glushkov , Evgenii S. Dentsel , Gevorg D. Manucharyan , Vyacheslav A. Sizov

This paper explores the generalized ghost dark energy model in the framework of $f(\textsl{Q}, \textsl{L}_{m})$ gravity, where $\textsl{Q}$ represents the non-metricity scalar and $\textsl{L}_{m}$ denotes the matter-Lagrangian density. We…

General Relativity and Quantum Cosmology · Physics 2025-01-03 M. Zeeshan Gul , M. Sharif , Shan Ali Qureshi , Baiju Dayanandan

Modified gravity (MG) theories predict, in general, that the ratio of gravitational wave (GW) to electromagnetic (EM) luminosity distances, $\Xi$, differs from its general relativity (GR) value of unity at cosmological scales, thus…

General Relativity and Quantum Cosmology · Physics 2021-05-28 Isabela S. Matos , Maurício O. Calvão , Ioav Waga

General Relativity is an extremely successful theory, at least for weak gravitational fields, however, it breaks down at very high energies, such as in correspondence of the initial singularity. Quantum Gravity is expected to provide more…

General Relativity and Quantum Cosmology · Physics 2023-04-20 Ana Rita Ribeiro , Daniele Vernieri , Francisco S. N. Lobo

In this work, we developed a cosmological model in $ f(Q, C) $ gravity within the framework of symmetric teleparallel geometry. In addition to the non-metricity scalar $Q $, our formulation includes the boundary term $ C $, which accounts…

General Relativity and Quantum Cosmology · Physics 2024-11-12 Shaily , J. K. Singh , Mohit Tyagi , Joao R. L. Santos

In this work, the cosmic solutions, particularly the well-known $\Lambda$CDM model, are investigated in the framework of the Gauss-Bonnet gravity, where the gravitational action incorporates the Gauss-Bonnet invariant function. We utilize a…

General Relativity and Quantum Cosmology · Physics 2024-09-26 N. Myrzakulov , Anirudh Pradhan , Archana Dixit , S. H. Shekh

We investigate the impact of modified-gravity models on the Lyman-$\alpha$ power spectrum. Building a simple analytical modeling, based on a truncated Zeldovich approximation, we estimate the intergalactic medium power spectrum and the…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-30 Philippe Brax , Patrick Valageas