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Related papers: Bouncing cosmological models in $f(R,L_m)$ gravity

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In this paper, the dynamical system analysis has been performed to analyze the dynamical behavior of the Universe in $f(R,L_m,T)$ gravity with a scalar field. A well motivated potential function and the linear form of the functional…

General Relativity and Quantum Cosmology · Physics 2026-04-21 R. R. Panchal , Divya G. Sanjava , A. H. Hasmani , B. Mishra

Motivated by the growing interest in the nonmetricity-matter couplings, we develop the scalar-tensor formulation of recently introduced $f(Q,T)$ gravity, where $Q$ is the nonmetricity and $T$ is the trace of the energy-momentum tensor. The…

General Relativity and Quantum Cosmology · Physics 2025-02-27 Adam Z. Kaczmarek , João Luís Rosa , Dominik Szczȩśniak

We examine the nonlinear dynamics of a closed Friedmann-Robertson-Walker universe in the framework of Brane World formalism with a timelike extra dimension. In this scenario, the Friedmann equations contain additional terms arising from the…

General Relativity and Quantum Cosmology · Physics 2015-06-12 Rodrigo Maier , Nelson Pinto-Neto , Ivano Damião Soares

We present a bounce universe in modified $f(Q,C)$ gravity considering linear as well as exponential form of gravity. Bounce cosmological models are introduced to remove the singularity problem of the early universe. A new quadratic boundary…

General Relativity and Quantum Cosmology · Physics 2025-08-07 Bhaswati Mandal , B. C. Paul

In this study, we explore the thermodynamic aspects of a modified version of Rastall's gravity theory and its implications for cosmological scenarios. We analyze the role of non-conserved energy-momentum tensor equations and investigate…

General Relativity and Quantum Cosmology · Physics 2025-12-01 José A. C. Nogales , K. Luz-Burgoa , Laysa G. Martins

This study delves into modified gravity theories that are equivalent to General Relativity but involve the torsion or non-metricity scalar instead of the curvature scalar. Specifically, we focus on $f(Q,T)$ gravity, which entails an…

General Relativity and Quantum Cosmology · Physics 2023-11-22 N. Myrzakulov , M. Koussour , Alnadhief H. A. Alfedeel , H. M. Elkhair

In this work we consider a cosmological scenario in which the Universe contracts initially having a bouncing-like behavior, and accordingly after it bounces off, it decelerates following a matter dominated like evolution and at very large…

General Relativity and Quantum Cosmology · Physics 2020-12-02 S. D. Odintsov , V. K. Oikonomou , Tanmoy Paul

We place observational constraints on an FLRW cosmological model in $f(R,L_m)$ gravity with a specific deceleration parameter that depends on the scale factor. This form of the deceleration parameter has been discussed by authors in several…

General Relativity and Quantum Cosmology · Physics 2024-12-30 Aroonkumar Beesham

In this paper, we study the dynamical behaviour of the Universe in the $F(R,G)$ theory of gravity, where $R$ and $G$ respectively denote the Ricci scalar and Gauss-Bonnet invariant. Our wide analysis encompasses the energy conditions,…

General Relativity and Quantum Cosmology · Physics 2022-04-22 Santosh V. Lohakare , S. K. Tripathy , B. Mishra

In this paper, we study a spatially homogeneous and isotropic FLRW cosmological model in framework of the symmetric teleparallel $f(Q)$ gravity proposed by Jimenez et al. (Physical Review D 98.4 (2018): 044048), where the non-metricity $Q$…

General Relativity and Quantum Cosmology · Physics 2022-08-30 M. Koussour , S. H. Shekh , M. Bennai

In the context of a ghost free $f(R,\mathcal{G})$ model, an extended matter bounce scenario is studied where the form of the scale factor is given by $a(t) = (a_0t^2 + 1)^n$. The ghost free character of the model is ensured by the presence…

General Relativity and Quantum Cosmology · Physics 2020-04-22 E. Elizalde , S. D. Odintsov , V. K. Oikonomou , Tanmoy Paul

It was recently realized that matter modeled by the scalar field sector of the Lee-Wick Standard Model yields, in the context of a homogeneous and isotropic cosmological background, a bouncing cosmology. However, bouncing cosmologies…

High Energy Physics - Theory · Physics 2015-03-17 Johanna Karouby , Robert Brandenberger

Extended $f(R)$ theories of gravity have been investigated from the symmetry point of view. We briefly has been investigated Noether symmetry of two types of extended $f(R)$ theories: $f(R,T)$ theory, in which curvature is coupled non…

General Relativity and Quantum Cosmology · Physics 2018-10-09 D. Momeni , R. Myrzakulov , E. Güdekli

We perform a phase space analysis of a non-minimally coupled modified gravity theory with the Lagrangian density of the form $\frac{1}{2} f_{1}(R)+[1+\lambda f_{2}(R)]{{\cal{L}}_{m}}$, where $f_1(R)$ and $f_2(R)$ are arbitrary functions of…

General Relativity and Quantum Cosmology · Physics 2014-06-03 Tahereh Azizi , Emad Yaraie

In this work, we use the dynamical system approach to explore the cosmological background evolution of the scalar-tensor representation of $f(R,T)$ gravity, where $R$ is the Ricci scalar and $T$ is the trace of the stress-energy tensor. The…

General Relativity and Quantum Cosmology · Physics 2024-04-04 Tiago B. Gonçalves , João Luís Rosa , Francisco S. N. Lobo

We extend the matter bounce scenario to a more general theory in which the background dynamics and cosmological perturbations are generated by a $k$-essence scalar field with an arbitrary sound speed. When the sound speed is small, the…

High Energy Physics - Theory · Physics 2017-03-17 Yu-Bin Li , Jerome Quintin , Dong-Gang Wang , Yi-Fu Cai

We consider the early time cosmology of f(R) theories in Palatini formalism and study the conditions that guarantee the existence of homogeneous and isotropic models that avoid the Big Bang singularity. We show that for such models the Big…

General Relativity and Quantum Cosmology · Physics 2009-10-24 Carlos Barragan , Gonzalo J. Olmo , Helios Sanchis-Alepuz

The behavior of the constants, G,c,h,a,e,m and Lambda, considering them as variable, in the framework of a flat cosmological model with FRW symmetries described by a bulk viscous fluid and considering mechanisms of adiabatic matter creation…

General Relativity and Quantum Cosmology · Physics 2014-11-17 J. A. Belinchon

In this article in a generalization of our previous work, we investigate the dynamics of the non-local $F(R)$ gravity after casting it into local form. The non-singular bouncing behavior and quintom model of dark energy are achieved without…

General Relativity and Quantum Cosmology · Physics 2015-05-30 H. Farajollahi , F. Tayebi , F. Milani , M. Enayati

In this paper, working in a Friedman-Lemaitre-Robertson-Walker (FLRW), first, in the flat case, we recover the generalized Friedman equation of Quantum Loop cosmology, and therefore the cosmological bounce, in the framework of modified…

General Relativity and Quantum Cosmology · Physics 2021-01-20 Alessandro Casalino , Bruno Sanna , Lorenzo Sebastiani , Sergio Zerbini
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