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Related papers: Past and future isotropization in $f(R)$ dark ener…

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We consider a dynamic scenario for characterizing the late Universe evolution, aiming to mitigate the Hubble tension. Specifically, we consider a metric $f(R)$ gravity in the Jordan frame which is implemented to the dynamics of a flat…

General Relativity and Quantum Cosmology · Physics 2024-08-06 Giovanni Montani , Nakia Carlevaro , Mariaveronica De Angelis

In this work, we will explore the effects of F(R) theories in the classical scheme using the anisotropic Bianchi Type I cosmological model with standard matter employing a barotropic fluid with equation of state $P=\gamma \rho$. In this…

General Relativity and Quantum Cosmology · Physics 2026-04-15 J. Socorro , Juan Luis Pérez , Luis Rey Díaz-Barrón , Abraham Espinoza García , Sinuhé Pérez Payán

We consider the cosmological evolution of a flat anisotropic Universe in $f(T)$ gravity in the presence of a perfect fluid. It is shown that the matter content of the Universe has a significant impact of the nature of a cosmological…

General Relativity and Quantum Cosmology · Physics 2021-06-10 Maria A. Skugoreva , Alexey V. Toporensky

We construct general anisotropic cosmological scenarios governed by an $f(R)$ gravitational sector. Focusing then on Kantowski-Sachs geometries in the case of $R^n$-gravity, and modelling the matter content as a perfect fluid, we perform a…

General Relativity and Quantum Cosmology · Physics 2011-08-19 Genly Leon , Emmanuel N. Saridakis

In this study, we explore the cosmological evolution of the Universe in the framework of covariant $f(Q)$ gravity, with a coupling function that evolves dynamically in proportion to the Hubble parameter. Two specific forms of the function…

General Relativity and Quantum Cosmology · Physics 2026-04-29 S. A. Narawade , S. A. Kadam

We consider a cosmological model in which the two major fluid components of the Universe, dark energy and dark matter, flow with distinct four-velocities. This cosmological configuration is equivalent to a single anisotropic fluid,…

General Relativity and Quantum Cosmology · Physics 2013-07-24 Tiberiu Harko , Francisco S. N. Lobo

The present study deals with spatially homogeneous and anisotropic locally rotationally symmetric (LRS) Bianchi type I cosmological model with dominance of dark energy. To get the deterministic model of Universe, we assume that the shear…

General Physics · Physics 2012-01-24 Anil Kumar Yadav , Bijan Saha

The dynamics of a self-gravitating neutron gas in presence of a magnetic field is being studied taking the equation of state of a magnetized neutron gas obtained in a previous study [2]. We work in a Bianchi I spacetime characterized by a…

Astrophysics · Physics 2008-10-15 D. Manreza Paret

We have investigated some bouncing cosmological models in an isotropic and homogeneous space time with the F(R) theory of gravity. Two functional forms of F(R) have been investigated with a bouncing scale factor. The dynamical parameters…

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

According to standard cosmology, the universe is homogeneous and isotropic at large scales. However, some anisotropies can be observed at the local scale in the universe through various ways. Here we have studied the Bianchi type I model…

General Relativity and Quantum Cosmology · Physics 2022-09-12 Pranjal Sarmah , Umananda Dev Goswami

In this work, we investigate the dynamics of the interacting dark energy and dark matter in viable models of $f(R)$ gravity by using a standard framework of dynamical system analysis. A simple form of the interacting dark energy $Q=3\alpha…

General Relativity and Quantum Cosmology · Physics 2021-09-22 Daris Samart , Bhuddhanubhap Silasan , Phongpichit Channuie

We present current and future constraints on the Hu and Sawicki modified gravity scenario. This model can reproduce a late time accelerated universe and evade solar system constraints. While current cosmological data still allows for…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Matteo Martinelli , Alessandro Melchiorri , Olga Mena , Valentina Salvatelli , Zahara Girones

We propose a new model of cosmology based on an anisotropic background and a specific $f(R)$ theory of gravity. It is shown that field equations of $f(R)$ gravity in a Bianchi type I background give rise to a modified Friedmann equation.…

General Relativity and Quantum Cosmology · Physics 2024-03-21 Cemsinan Deliduman , Oguzhan Kasikci , Vildan Keles Tugyanoglu

The role of anisotropic components on the dark energy and the dynamics of the universe is investigated. An anisotropic dark energy fluid with different pressures along different spatial directions is assumed to incorporate the effect of…

General Physics · Physics 2018-04-16 B. Mishra , S. K. Tripathy , Pratik P Ray

Modified gravity theories can be used for the description of homogeneous and isotropic cosmological models through the corresponding field equations. These can be cast into systems of autonomous differential equations because of their sole…

General Relativity and Quantum Cosmology · Physics 2024-04-08 Christian G. Boehmer , Erik Jensko , Ruth Lazkoz

The dynamics and evolution of Bianchi type I space-times is considered in the framework of the four-dimensional truncation of a reduced theory obtained from the N=2,D=5 supergravity. The general solution of the gravitational field equations…

High Energy Physics - Theory · Physics 2009-10-31 Chiang-Mei Chen , T. Harko , M. K. Mak

Recently a Born-Infeld action for dark energy and dark matter that uses additional affine connections was proposed. At background level, it was shown that the new proposal can mimic the standard cosmological evolution. In Bianchi…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Davi C. Rodrigues

Anisotropic Bianchi-III cosmological model is investigated with variable gravitational and cosmological constants in the framework of Einstein's general relativity. The shear scalar is considered to be proportional to the expansion scalar.…

General Relativity and Quantum Cosmology · Physics 2015-06-23 S. K. Tripathy , D. Behera , T. R. Routray

The possible anisotropic nature in the early phases of the Universe is one of the interesting aspects of study in cosmology. We investigate the evolution of the Universe in terms of few cosmological parameters considering an anisotropic…

General Relativity and Quantum Cosmology · Physics 2023-04-03 Pranjal Sarmah , Avik De , Umananda Dev Goswami

We study the dynamics of the Bianchi I universe in modified loop quantum cosmology (mLQC-I) and uncover a robust mechanism for isotropization: the shear is dynamically suppressed after the bounce and decays rapidly in the quantum…

General Relativity and Quantum Cosmology · Physics 2026-05-26 Wen-Cong Gan , Leila L. Graef , Rudnei O. Ramos , Gustavo S. Vicente , Anzhong Wang