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Related papers: Raychaudhuri equation and the dynamics of cosmic e…

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We present a new avenue of the Raychaudhuri Equation (RE) by introducing a non-affine parametrization within the k-essence framework. This modification accounts for non-geodesic flow curves, leading to emergent repulsive effects in cosmic…

General Relativity and Quantum Cosmology · Physics 2025-06-06 Samit Ganguly , Goutam Manna , Debashis Gangopadhyay , Eduardo Guendelman , Abhijit Bhattacharyya

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

The paper deals with a suitable transformation related to the metric scalar of the hyper-surface so that the Raychaudhuri Equation (RE) can be written as a second order nonlinear differential equation. A first integral of this second order…

General Relativity and Quantum Cosmology · Physics 2023-06-30 Madhukrishna Chakraborty , Subenoy Chakraborty

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

The paper deals with the modified Raychaudhuri equation (RE) within the framework of homogeneous and isotropic Fractal Universe. Focusing of a congruence of time-like geodesics has been examined for three generic choices of the fractal…

General Relativity and Quantum Cosmology · Physics 2024-11-06 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

The Raychaudhuri equation for a congruence of curves in a general non-Riemannian geometry is derived. A formal connection is established between the expansion scalar and the cross-sectional volume of the congruence. It is found that the…

General Relativity and Quantum Cosmology · Physics 2024-06-18 Anish Agashe

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 study the evolution of timelike geodesics for two dimensional black hole spacetimes arising in string theory and general theory of relativity by solving the Raychaudhuri equation for expansion scalar as an initial value problem. The…

General Relativity and Quantum Cosmology · Physics 2015-05-04 Ravi Shankar Kuniyal , Rashmi Uniyal , Hemwati Nandan , Alia Zaidi

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

The geodesic deviation equation, describing the relative accelerations of nearby particles, and the Raychaudhury equation, giving the evolution of the kinematical quantities associated with deformations (expansion, shear and rotation) are…

General Relativity and Quantum Cosmology · Physics 2012-12-20 Tiberiu Harko , Francisco S. N. Lobo

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

We study the accelerated expansion of the Universe through its consequences on a congruence of geodesics. We make use of the Raychaudhuri equation which describes the evolution of the expansion rate for a congruence of timelike or null…

General Relativity and Quantum Cosmology · Physics 2013-01-09 F. D. Albareti , J. A. R. Cembranos , A. de la Cruz-Dombriz

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

Peculiar motions are commonplace in the universe. Our local group of galaxies, for example, drifts relative to the Hubble flow at about 600 km/sec. Such bulk flows are believed to fade away as we move on to progressively larger scales.…

General Relativity and Quantum Cosmology · Physics 2015-06-16 Christos G. Tsagas , Miltiadis I. Kadiltzoglou

In General Relativity, gravity is universally attractive, a feature embodied by the Raychaudhuri equation which requires that the expansion of a congruence of geodesics is always non-increasing, as long as matter obeys the strong or weak…

General Relativity and Quantum Cosmology · Physics 2018-07-09 Daniel J Burger , Saurya Das , S. Shajidul Haque , Nathan Moynihan , Bret Underwood

Gravitational waves (GWs) are independent of any particular theory of gravity. The universality of this notion is highlighted by the Raychaudhuri equation (RE), which is independent of any theory of gravity and contains the Ricci tensor…

General Relativity and Quantum Cosmology · Physics 2025-09-29 Sougata Bhunia , Anubhab Dutta , Debashis Gangopadhyay , Goutam Manna

We investigate the evolution of timelike geodesic congruences, in the background of a charged black hole spacetime surrounded with quintessence. The Raychaudhuri equations for three kinematical quantities namely the expansion scalar, shear…

General Relativity and Quantum Cosmology · Physics 2018-03-12 Hemwati Nandan , Rashmi Uniyal

We generalize the Raychaudhuri equation for the evolution of a self gravitating fluid to include an Abelian and non-Abelian hybrid magneto fluid at a finite temperature. The aim is to utilize this equation for investigating the dynamics of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Chandrasekher Mukku , Swadesh M. Mahajan , Bindu A. Bambah

In General Relativity without a cosmological constant a non-positive contribution from the space-time geometry to Raychaudhuri equation is found provided that particular energy conditions are assumed and regardless the considered solution…

General Relativity and Quantum Cosmology · Physics 2013-07-10 F. D. Albareti , J. A. R. Cembranos , A. de la Cruz-Dombriz , A. Dobado
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