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In this work, we examine the implications of $q$-deformed theory on anisotropic Bianchi type-I cosmological model within the framework of Verlinde's entropic gravity. The $q$-deformed theory, rooted in quantum group structures, provides a…

General Relativity and Quantum Cosmology · Physics 2025-02-05 Salih Kibaroğlu , Mustafa Senay

We construct exact solutions representing a Friedmann-Lema\^itre-Robsertson-Walker (FLRW) universe in a generalized hybrid metric-Palatini theory. By writing the gravitational action in a scalar-tensor representation, the new solutions are…

General Relativity and Quantum Cosmology · Physics 2017-07-18 João L. Rosa , Sante Carloni , José P. S. Lemos , Francisco S. N. Lobo

We examine homogeneous but anisotropic cosmologies in scalar-tensor gravity theories, including Brans-Dicke gravity. We present a method for deriving solutions for any isotropic perfect fluid with a barotropic equation of state…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Jose P. Mimoso , David Wands

This paper is devoted to investigate the exact solutions of Bianchi types I and V spacetimes in the context of f(R, T) gravity [1]. For this purpose, we found two exact solutions in each case by using assumption of constant deceleration…

General Relativity and Quantum Cosmology · Physics 2012-07-04 M. Farasat Shamir , Adil Jhangeer , Akhlaq Ahmad Bhatti

We present an exact analytical solution of the Einstein equations with cosmological constant in a spatially flat Robertson-Walker metric. This is interpreted as an isotropic Lemaitre-type version of the cosmological Friedmann model.…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Ion I. Cotaescu , Dumitru N. Vulcanov

We present the classical solutions to the Einstein field equations derived using the WKB-like and Hamilton procedures. The investigation is carried out in the commutative and noncommutative scenario for the Bianchi type I cosmological model…

General Relativity and Quantum Cosmology · Physics 2009-11-13 C. Ortiz , E. Mena-Barboza , M. Sabido , J. Socorro

We construct the $F(R)$ gravity models with exact particular solutions using the conformal transformation and the superpotential method for the corresponding models in the Einstein frame. The functions $F(R)$ are obtained explicitly. We…

General Relativity and Quantum Cosmology · Physics 2020-10-06 S. Yu. Vernov , V. R. Ivanov , E. O. Pozdeeva

The variety of theories that can account for the dark energy phenomenon encourages current research to concentrate on a more in-depth examination of the potential impacts of modified gravity on both local and cosmic scales. We discuss some…

General Relativity and Quantum Cosmology · Physics 2023-01-27 Gaurav N. Gadbail , Simran Arora , P. K. Sahoo

In a homogenous and isotropic cosmology, we introduce general exact solutions for some modified gravity models. In particular, we introduce exact solutions for power-law $f(R)$ gravity and Brans-Dicke theory in Einstein and Jordan conformal…

High Energy Physics - Theory · Physics 2018-06-08 Yousef Bisabr

In this paper, we discuss the Bianchi type-I cosmological model in the framework of symmetric teleparallel gravity say $f(Q)$ gravity in which the non-metricity term $Q$ is responsible for the gravitational interaction. We consider a…

General Relativity and Quantum Cosmology · Physics 2023-04-05 M. Koussour , S. H. Shekh , M. Govender , M. Bennai

The "improved dynamics" of loop quantum cosmology is extended to include anisotropies of the Bianchi I model. As in the isotropic case, a massless scalar field serves as a relational time parameter. However, the extension is non-trivial…

General Relativity and Quantum Cosmology · Physics 2010-04-14 Abhay Ashtekar , Edward Wilson-Ewing

The use of techniques from loop quantum gravity for cosmological models may solve some difficult problems in quantum cosmology. The solutions under a number of circumstances have been well studied. We will analyse the behaviour of solutions…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Daniel Green , William G. Unruh

We re-investigate how generic off-diagonal cosmological solutions depending, in general, on all spacetime coordinates can be constructed in massive and f-modified gravity using the anholonomic frame deformation method. There are constructed…

General Relativity and Quantum Cosmology · Physics 2015-05-06 Sergiu I. Vacaru

We study the homogeneous but anisotropic Bianchi type-V cosmological model with time-dependent gravitational and cosmological "constants". Exact solutions of the Einstein field equations (EFEs) are presented in terms of adjustable…

General Relativity and Quantum Cosmology · Physics 2018-07-30 Alnadhief H. A. Alfedeel , Amare Abebe , Hussam M. Gubara

In this paper we study the dynamics of {\it orthogonal spatially homogeneous} Bianchi cosmologies in $R^n$-gravity. We construct a compact state space by dividing the state space into different sectors. We perform a detailed analysis of the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Naureen Goheer , Jannie A. Leach , Peter K. S. Dunsby

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

We use one of the simplest forms of the K-essence theory and we apply it to the classical anisotropic Bianchi type I cosmological model, with a barotropic perfect fluid modeling the usual matter content and with cosmological constant. The…

General Relativity and Quantum Cosmology · Physics 2014-09-11 J. Socorro , Luis O. Pimentel , Abraham Espinoza-García

In this paper, we investigate the exact solution of an anisotropic space-time in the context of $f(Q)$ gravity, where $f\left( Q\right) $ is the arbitrary function of the non-metricity scalar $Q$. Here, we consider a specific power-law form…

General Relativity and Quantum Cosmology · Physics 2022-12-01 M. Koussour , M. Bennai

We present the data-driven reconstruction of gravitational theories and Dark Energy models on cosmological scales. We showcase the power of present cosmological probes at constraining these models and quantify the knowledge of their…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-22 Marco Raveri

We consider gravity mediated by non-metricity, with vanishing curvature and torsion. The gravitational action, including an arbitrary function of the non-metric scalar, is investigated in view of characterizing the dark energy effects. In…

General Relativity and Quantum Cosmology · Physics 2022-07-13 Salvatore Capozziello , Rocco D'Agostino