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The main objective of this manuscript is to investigate the bouncing cosmology in the background of $f(\mathcal{Q})$ gravity, where $\mathcal{Q}$ defines the non-metricity. For this purpose, we use the reconstruction approach and consider a…

General Relativity and Quantum Cosmology · Physics 2024-04-02 M. Sharif , M. Zeeshan Gul , Nusrat Fatima

In this article, we present a generic dynamical system formulation for Bianchi-I cosmology in the presence of an isotropic fluid within the coincident gauge connection branch and one of the non-coincident gauge connection branches of $f(Q)$…

General Relativity and Quantum Cosmology · Physics 2025-09-03 Ghulam Murtaza , Saikat Chakraborty , Avik De

We use a dynamical systems approach to investigate Bianchi type I and II universes in quadratic theories of gravity. Due to the complicated nature of the equations of motion we focus on the stability of exact solutions and find that there…

General Relativity and Quantum Cosmology · Physics 2008-11-26 John D. Barrow , Sigbjorn Hervik

Bianchi type III (BIII) metric is an interesting anisotropic model for studying cosmic anisotropy as it has an additional exponential term multiplied to a directional scale factor. Thus, the cosmological parameters obtained for this BIII…

General Relativity and Quantum Cosmology · Physics 2025-09-03 Pranjal Sarmah , Umananda Dev Goswami

In this paper, we study $F(R)$ gravity by Hu-Sawicki model in Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) background. The Friedmann equations are calculated by modified gravity action, and then the obtained Friedmann equations are…

General Relativity and Quantum Cosmology · Physics 2016-05-25 Ali R. Amani

Aims: In view of the substantial uncertainties regarding the possible dynamics of the dark energy, we aim at constraining the expansion rate of the universe without reference to a specific Friedmann model and its parameters. Methods: We…

Astrophysics · Physics 2008-04-08 Claudia Mignone , Matthias Bartelmann

The Asymptotically Safe Gravity provides a framework for the description of gravity from the trans-Planckian regime to cosmological scales. According to this scenario, the cosmological constant and Newton's coupling are functions of the…

General Relativity and Quantum Cosmology · Physics 2018-03-14 Alfio Bonanno , Gabriele Gionti , Alessia Platania

In this paper, we study the main cosmological properties of the classical Friedmann equations in the case of homogeneous and isotropic Friedmann-Robertson-Walker Universe and we also generalized the expression of the Friedmann equation in…

General Relativity and Quantum Cosmology · Physics 2014-03-13 S. Chattopadhyay , A. Ashurov , M. Khurshudyan , K. Myrzakulov , A. Pasqua , R. Myrzakulov

Cosmography can be considered as a sort of a model-independent approach to tackle the dark energy/modified gravity problem. In this review, the success and the shortcomings of the $\Lambda$CDM model, based on General Relativity and standard…

General Relativity and Quantum Cosmology · Physics 2019-04-09 Salvatore Capozziello , Rocco D'Agostino , Orlando Luongo

Loop Quantum Cosmology (LQC) is a theory which renders the Big Bang initial singularity into a quantum bounce, by means of short range repulsive quantum effects at the Planck scale. In this work, we are interested in reproducing the…

General Relativity and Quantum Cosmology · Physics 2021-11-25 Marcello Miranda , Daniele Vernieri , Salvatore Capozziello , Francisco S. N. Lobo

A Bianchi type-I cosmological model in the presence of a magnetic flux along a cosmological string is investigated. The objective of this study is to generate solutions to the Einstein equations using a few tractable assumptions usually…

General Relativity and Quantum Cosmology · Physics 2015-05-13 Bijan Saha , Victor Rikhvitsky , Mihai Visinescu

We derive exact solutions to the vacuum Einstein field equations in 5D, under the assumption that (i) the line element in 5D possesses self-similar symmetry, in the classical understanding of Sedov, Taub and Zeldovich, and that (ii) the…

General Relativity and Quantum Cosmology · Physics 2009-03-12 J. Ponce de Leon

This thesis explores the late-time cosmic acceleration within the framework of $f(R,T)$ gravity, a general relativity modification that incorporates the Ricci scalar $R$ and the trace of the energy-momentum tensor $T$. Motivated by…

General Relativity and Quantum Cosmology · Physics 2025-07-29 Parbati Sahoo

In this paper, we consider a non-static spherical geometry and formulate its extension for the case of anisotropic matter configuration through minimal gravitational decoupling in $f(\mathbb{R},\mathbb{T})$ theory. We apply a particular…

General Relativity and Quantum Cosmology · Physics 2023-07-12 Tayyab Naseer , M. Sharif

The Friedmann-Robertson-Walker (FRW) universe and Bianchi I,II universes are investigated in the framework of the generalized uncertainty principle (GUP) with a linear and a quadratic term in Planck length and momentum, which predicts…

General Relativity and Quantum Cosmology · Physics 2014-10-21 Ahmed Farag Ali , Barun Majumder

LRS Bianchi type-I models have been studied in the cosmological theory based on Lyra's geometry. A new class of exact solutions has been obtained by considering a time dependent displacement field for variable deceleration parameter models…

General Relativity and Quantum Cosmology · Physics 2010-05-28 Anirudh Pradhan , D. S. Chauhan

We consider cosmological scenarios based on $f(R,T)$ theories of gravity ($R$ is the Ricci scalar and $T$ is the trace of the energy-momentum tensor) and numerically reconstruct the function $f(R,T)$ which is able to reproduce the same…

General Relativity and Quantum Cosmology · Physics 2015-03-19 M. J. S. Houndjo , Oliver F. Piattella

This paper discusses a simple procedure to reconstruct f (R)-gravity models from exact cosmological solutions of the Einstein field equations with a noninteracting classical scalar field-and-radiation background. From the kind of…

General Relativity and Quantum Cosmology · Physics 2017-09-15 Heba Sami , Joseph Ntahompagaze , Amare Abebe

Isotropic cosmological singularities are singularities which can be removed by rescaling the metric. In some cases already studied (gr-qc/9903008, gr-qc/9903009, gr-qc/9903018) existence and uniqueness of cosmological models with data at…

General Relativity and Quantum Cosmology · Physics 2017-08-23 K. P. Tod

Motivated by the newly proposal for gravity as the effect of the torsion scalar $T$ and trace of the energy momentum tensor $\mathcal{T}$,we investigate the cosmological reconstruction of different models of the Universe. Our aim here is to…

General Relativity and Quantum Cosmology · Physics 2018-10-09 Davood Momeni , Ratbay Myrzakulov