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In this work we shall investigate the occurrence of future cosmological finite-time singularities in the dynamical system corresponding to two cosmological theories, namely that of vacuum $f(R)$ gravity and that of three fluids. The vacuum…

General Relativity and Quantum Cosmology · Physics 2018-08-01 S. D. Odintsov , V. K. Oikonomou

A new kind of evolution for cyclic models in which the Hubble parameter oscillates and keeps positive has been explored in a specific $f(R,T)$ gravity reconstruction. A singularity-free cyclic universe with negative varying cosmological…

General Relativity and Quantum Cosmology · Physics 2019-02-11 Nasr Ahmed , Sultan Z. Alamri

We present a novel approach for reconstructing the $f(Q)$ gravitational theory using parameterizations of the deceleration parameter or alternative options. This method enables the development of modified gravity scenarios that align with…

General Relativity and Quantum Cosmology · Physics 2025-02-26 G. G. L. Nashed

In the context of f(R, T) gravity theory for the flat Friedmann Lemaitre Robertson Walker (FLRW) model, the accelerating expansion of the universe is investigated using a specific form of the emergent Hubble parameter. Datasets from H(z),…

General Relativity and Quantum Cosmology · Physics 2025-01-16 N. Myrzakulov , S. H. Shekh , Anirudh Pradhan , Archana Dixit

Although big bang cosmology effectively models even the most puzzling observational data, it offers no insight into why the cosmological expansion should occur at all. In this paper it is suggested that a finite Universe poses particular…

General Physics · Physics 2007-05-23 Alasdair Macleod

In this paper, we have presented the cosmological model of the Universe that represents late time cosmic acceleration in torsion based gravitational theory, the $f(T)$ gravity. A well motivated parametrization for the Hubble parameter has…

General Relativity and Quantum Cosmology · Physics 2025-11-04 Suraj Kumar Behera , Pratik P. Ray , B. Mishra

The present search focus on the mechanism of gravitationally influenced particle creation (PC) in higher dimensional Friedmann-Lemaitre-Robertson-Walker(FLRW) cosmological models with a cosmological constant (CC). The solution of the…

General Physics · Physics 2022-05-18 Priyanka Garg , Anirudh Pradhan

A detailed analysis of gravitational slip, a new post-general relativity cosmological parameter characterizing the degree of departure of the laws of gravitation from general relativity on cosmological scales, is presented. This…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-18 Scott F. Daniel , Robert R. Caldwell , Asantha Cooray , Paolo Serra , Alessandro Melchiorri

We study cosmologies in modified theories of gravity considering Lagrangian density $f(R)$ which is a polynomial function of scalar curvature ($R$) in the Einstein-Hilbert action in vacuum. The field equation obtained from the modified…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-29 B. C. Paul , P. S. Debnath , S. Ghose

In this paper, a cosmological model of the Universe is presented in $f(Q,T)$ gravity and the parameters are constrained by cosmological data sets. Initially, a generalised form of $f(Q,T)$ model is used as $f(Q,T)=-\lambda_{1}…

General Relativity and Quantum Cosmology · Physics 2024-03-21 A. S. Agrawal , B. Mishra , S. K. Tripathy

In this paper, we propose a simple parametrization of the Hubble parameter H in order to explain the late time cosmic acceleration. We show that our proposal covers many models obtained in different schemes of parametrization under one…

General Relativity and Quantum Cosmology · Physics 2022-07-20 S. K. J. Pacif , R. Myrzakulov , S. Myrzakul

We determine a cosmological model that include a positive acceleration of the Universe and a time decreasing fine structure constant. The present day deceleration parameter is estimated by us, according to our model and the available…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Marcelo S. Berman , Luis A. Trevisan

In this investigation we discuss the dynamical aspects of Kaluza-Klein FRW type cosmological model in the presence of dark energy fluid and an attractive massive scalar field. The field equations are solved using a power law between the…

General Physics · Physics 2019-11-07 D. R. K. Reddy , K. Deniel Raju

The cosmological dynamics in the early universe are investigated to explore the possibility of the sign reversal of the Hubble parameter as a key feature of non-singular bouncing cosmological solutions in higher-order torsion gravity. The…

General Relativity and Quantum Cosmology · Physics 2026-03-31 Adnan Malik , Aimen Rauf , Kazuharu Bamba , Wenbin Lin , Fatemah Mofarreh

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

We consider f(R) modified gravity theories for describing varying speed of light in a spatially flat FRW model, and find some exact solutions. Also we examine the dynamics of this model by dynamical system method assuming a LambdaCDM…

General Relativity and Quantum Cosmology · Physics 2010-02-02 Azam Izadi , Ali Shojai

Two parameters scale factor leading to bouncing cosmology is considered. We show that at some model parameters we obtain the deceleration parameter $q_0\approx -0.535$ at the current epoch which is in agreement with the Planck data. The…

General Physics · Physics 2026-05-18 S. I. Kruglov

A general-relativistic theory of cosmology, the dynamical variables of which are those of Hubble's, namely distances and redshifts, is presented. The theory describes the universe as having a three-phase evolution with a decelerating…

Astrophysics · Physics 2007-05-23 S. Behar , M. Carmeli

We have probed a cosmological model in $f(R)$-gravity, which is a cubic equation in scalar curvature $R$. The terms arise due to nonlinear $f(R)$ function are treated as energy due to curvature inspired geometry. As a result, we find…

General Relativity and Quantum Cosmology · Physics 2023-05-03 G. K. Goswami , Rita Rani , Harshna Balhara , J. K. Singh

This work aims to study consequences of \textit{combined variable field theory} developed in [1] by analysing FLRW models of gravity. It shows $\Phi_{q \rightarrow 0} \rightarrow \infty$ is the Big bang in combined variable field theoretic…

General Relativity and Quantum Cosmology · Physics 2018-05-14 Avadhut Purohit