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Related papers: On the consequences of Raychaudhuri equation in Ka…

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The paper aims at deriving a curvature form of the famous Raychaudhuri equation (RE) and the associated criteria for focusing of a hyper-surface orthogonal congruence of time-like geodesic. Moreover, the paper identifies a transformation of…

General Relativity and Quantum Cosmology · Physics 2024-10-01 Madhukrishna Chakraborty , Subenoy Chakraborty

In general description of the Raychaudhuri equation it is found that this first order non-linear differential equation can be written as a second order linear differential equation in the form of Harmonic Oscillator with varying frequency.…

General Relativity and Quantum Cosmology · Physics 2023-02-20 Madhukrishna Chakraborty , Akash Bose , Subenoy Chakraborty

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

The present work deals with the Raychaudhuri equation (RE) to examine the space-time singularity both from classical and quantum point of view. The RE has been looked upon in terms of a classical linear Harmonic oscillator and Focusing…

General Relativity and Quantum Cosmology · Physics 2024-09-24 Madhukrishna Chakraborty , Subenoy Chakraborty

The present work deals with an exhaustive study of bouncing cosmology in the background of homogeneous and isotropic Friedmann-Lemaitre-Robertson-Walker space-time. The geometry of the bouncing point has been studied extensively and used as…

General Relativity and Quantum Cosmology · Physics 2023-08-22 Madhukrishna Chakraborty , Subenoy Chakraborty

In this paper we investigate the fate of the universe with an anisotropic background sourced by anisotropic matter. We see the behaviour of the Raychaudhuri Equation and investigate wheather a congrurence of time like geodesics focus to a…

General Relativity and Quantum Cosmology · Physics 2015-09-23 Manabendra Sharma

We introduce and develop the 1+3 covariant approach to relativity and cosmology to spacetimes of arbitrary dimensions that have nonzero torsion and do not satisfy the metricity condition. Focusing on timelike observers, we identify and…

General Relativity and Quantum Cosmology · Physics 2018-12-05 Damianos Iosifidis , Christos G. Tsagas , Anastasios C. Petkou

The simplest anisotropic model of the early Universe is the one with two conformal factors, which can be identified as Kantowski-Sachs metric, or the reduced version of the Bianchi-I metric. To fit the existing observational data, it is…

General Relativity and Quantum Cosmology · Physics 2023-12-11 Vinicius G. Oliveira , Gil de Oliveira-Neto , Ilya L. Shapiro

We explore the phase-space of homogeneous and anisotropic spacetimes within symmetric teleparallel $f(Q)$-gravity. Specifically, we consider the Kantowski-Sachs and locally rotational Bianchi III geometries to describe the physical space.…

General Relativity and Quantum Cosmology · Physics 2024-03-12 Alfredo D. Millano , K. Dialektopoulos , N. Dimakis , A. Giacomini , H. Shababi , Amlan Halder , A. Paliathanasis

Although it is not a fundamental question, to determine exact and general solutions for a given theory has advantages over a numerical integration in many specific cases. Of course, respecting the peculiarities of the problem. Revisiting…

General Relativity and Quantum Cosmology · Physics 2019-11-12 B. Terezon , M. Campos

We study the singularity of the congruences for both timelike and null geodesic curves using the expansion of the early anisotropic Bianchi type I Universe. In this paper, we concentrate on the influence of the shear of the timelike and…

General Relativity and Quantum Cosmology · Physics 2016-04-27 Yoogeun Song , Seok Jae Park

The loop quantum dynamics of Kantowski-Sachs spacetime and the interior of higher genus black hole spacetimes with a cosmological constant has some peculiar features not shared by various other spacetimes in loop quantum cosmology. As in…

General Relativity and Quantum Cosmology · Physics 2015-09-29 Naresh Dadhich , Anton Joe , Parampreet Singh

In this paper, we analyze the anisotropy of the scale factor in the Kantowski-Sachs spacetime. We show that the anisotropy will not increase when the expansion rate is greater than certain values while it will increase when the expansion…

High Energy Physics - Theory · Physics 2007-05-23 Jian-gang Hao , Xin-zhou Li

The paper deals with the Raychaudhuri equation (RE) which is a non-linear ordinary differential equation in $\Theta$, the expansion scalar corresponding to a geodesic flow. Focusing theorem which follows as a consequence of the RE has been…

General Relativity and Quantum Cosmology · Physics 2024-02-29 Madhukrishna Chakraborty , Subenoy Chakraborty

Implications of the Raychaudhuri equation in focusing of geodesic congruences are studied in the framework of scalar--tensor theory of gravity. Specifically, we investigate the Brans--Dicke theory and Bekenstein's scalar field theory. In…

General Relativity and Quantum Cosmology · Physics 2022-08-30 Shibendu Gupta Choudhury , Ananda Dasgupta , Narayan Banerjee

This article investigates the modified Raychaudhuri Equation (RE) in the context of Non-Gravitating Vacuum Energy (NGVE) theory and its implications for various cosmological characteristics. The equation is formulated based on the NGVE…

General Relativity and Quantum Cosmology · Physics 2025-06-06 Arijit Panda , Eduardo Guendelman , Goutam Manna

We consider the brane Kantowski-Sachs universe when bulk space is five dimensional anti-de Sitter obeying a linear equation of state of the form $p=(\gamma -1)\rho +p_{0}$, where $ \gamma,\:p_{0}$ are a parameters. In this framework we…

General Relativity and Quantum Cosmology · Physics 2015-12-02 G. S. Khadekar

In the present work, we study the dynamical evolution of an homogeneous and anisotropic KS cosmological model, considering general relativity as the gravitational theory, such that there are three different perfect fluids in the matter…

General Relativity and Quantum Cosmology · Physics 2022-06-15 G. Oliveira-Neto , D. L. Canedo , G. A. Monerat

Raychaudhuri equation is derived by assuming geometric flow in spacetime M of n+1 dimensions. The equation turns into a harmonic oscillator form under suitable transformations.Thereby a relation between geometrical entropy and mean geodesic…

General Relativity and Quantum Cosmology · Physics 2021-04-13 Lawrence Paul Horwitz , Vishnu S Namboothiri , Gautham Varma K , Asher Yahalom , Yossi Strauss , Jacob Levitan

We investigate how the Raychaudhuri equation behaves in the $k$-essence geometry. As far as we are concerned, both the early and current epochs of the universe are relevant to the $k$-essence theory. Here, we have studied the $k$-essence…

General Relativity and Quantum Cosmology · Physics 2023-03-07 Surajit Das , Arijit Panda , Goutam Manna , Saibal Ray
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