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Related papers: Comment on "Quantum Raychaudhuri equation"

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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

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

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 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

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

The classical Raychaudhuri equation predicts the formation of conjugate points for a congruence of geodesics, in a finite proper time. This in conjunction with the Hawking-Penrose singularity theorems predicts the incompleteness of…

General Relativity and Quantum Cosmology · Physics 2021-09-16 Keagan Blanchette , Saurya Das , Saeed Rastgoo

In this work we present a derivation of modified Raychaudhuri and Friedmann equations from a phenomenological model of quantum gravity based on the thermodynamics of spacetime. Starting from general gravitational equations of motion which…

General Relativity and Quantum Cosmology · Physics 2023-09-13 Ana Alonso-Serrano , Marek Liška , Antonio Vicente-Becerril

Raychaudhuri equation is generalized in the parameterized absolute parallelism geometry. This version of absolute parallelism is more general than the conventional one. The generalization takes into account the suggested interaction between…

General Relativity and Quantum Cosmology · Physics 2009-11-05 M. I. Wanas , M. A. Bakry

In a previous article [H. Bergeron, J. Math. Phys. 42, 3983 (2001)], we presented a method to obtain a continuous transition from classical to quantum mechanics starting from the usual phase space formulation of classical mechanics. This…

Quantum Physics · Physics 2007-05-23 H. Bergeron

The problem of obtaining canonical Hamiltonian structures from the equations of motion, without any knowledge of the action, is studied in the context of the spatially flat Friedmann-Robertson-Walker models. Modifications to Raychaudhuri…

General Relativity and Quantum Cosmology · Physics 2016-05-18 Parampreet Singh , S. K. Soni

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

Different approaches are compared to formulation of quantum mechanics of a particle on the curved spaces. At first, the canonical, quasi-classical and path integration formalisms are considered for quantization of geodesic motion on the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 E. A. Tagirov

I discuss singular spacetimes in the context of the geometrized formulation of Newtonian gravitation. I argue first that geodesic incompleteness is a natural criterion for when a model of geometrized Newtonian gravitation is singular, and…

Classical Physics · Physics 2013-08-09 James Owen Weatherall

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 effects on Raychaudhuri's equation of an intrinsically-discrete or particle nature of spacetime are investigated. This is done through the consideration of null congruences emerging from, or converging to, a generic point of spacetime,…

General Relativity and Quantum Cosmology · Physics 2022-10-12 Alessandro Pesci

We shall investigate the properties of a congruence of geodesics in the framework of Palatini f(R) theories. We shall evaluate the modified geodesic deviation equation and the Raychaudhuri's equation and show that f(R) Palatini theories do…

General Relativity and Quantum Cosmology · Physics 2008-12-18 Fatimah Shojai , Ali Shojai

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 role of the Raychaudhuri equation in studying gravitational collapse is discussed. A self-similar distribution of a scalar field along with an imperfect fluid in a conformally flat spacetime is considered for the purpose. The general…

General Relativity and Quantum Cosmology · Physics 2019-12-30 Shibendu Gupta Choudhury , Soumya Chakrabarti , Ananda Dasgupta , Narayan Banerjee

The singularity theorems of classical general relativity are briefly reviewed. The extent to which their conclusions might still apply when quantum theory is taken into account is discussed. There are two distinct quantum loopholes: quantum…

General Relativity and Quantum Cosmology · Physics 2007-05-23 L. H. Ford

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