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Related papers: Raychaudhuri equation in scalar-tensor theory

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In this article, we study the form of deviation of geodesics (tidal forces) and Raychaudhuri equation in a Schwarzshild-Finsler-Randers (SFR) spacetime which has been investigated in previous papers. This model is obtained by considering…

General Relativity and Quantum Cosmology · Physics 2024-01-10 A. Triantafyllopoulos , E. Kapsabelis , P. C. Stavrinos

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 consider the Brans-Dicke theory in non-metricity gravity, which belongs to the family of symmetric teleparallel scalar-tensor theories. Our focus lies in exploring the implications of the conformal transformation, as we derive the…

General Relativity and Quantum Cosmology · Physics 2023-10-26 Andronikos Paliathanasis

We show that the field equation of Brans-Dicke gravity and scalar-tensor gravity can be derived as the equation of state of Rindler spacetime, where the local thermodynamic equilibrium is maintained. Our derivation implies that the…

High Energy Physics - Theory · Physics 2008-12-18 Shao-Feng Wu , Guo-Hong Yang , Peng-Ming Zhang

The works reported in this thesis primarily address the application of the Raychaudhuri equation in two intriguing problems in gravitational physics. These problems still lack universally accepted explanations. The first problem is related…

General Relativity and Quantum Cosmology · Physics 2023-01-20 Shibendu Gupta Choudhury

We analyze the cosmology of a general Scalar-Tensor theory which encompasses generalized Brans-Dicke theory, Gauss-Bonnet gravity, non-minimal derivative gravity, generalized Galileon gravity and also the general k-essence type models.…

General Relativity and Quantum Cosmology · Physics 2017-03-07 Erfan Masaeli , Meysam Motaharfar , Hamid Reza Sepangi

Two different ways of generalizing Einstein's general theory of relativity with a cosmological constant to Brans-Dicke type scalar-tensor theories are investigated in the linearized field approximation. In the first case a cosmological…

General Relativity and Quantum Cosmology · Physics 2018-02-07 Hatice Özer , Özgür Delice

The Raychaudhuri equation for a geodesic congruence in the presence of a zero-point length has been investigated. This is directly related to the small-scale structure of spacetime and possibly captures some quantum gravity effects. The…

General Relativity and Quantum Cosmology · Physics 2019-09-04 Sumanta Chakraborty , Dawood Kothawala , Alessandro Pesci

The qualitative properties of spatially homogeneous stiff perfect fluid and minimally coupled massless scalar field models within general relativity are discussed. Consequently, by exploiting the formal equivalence under conformal…

Astrophysics · Physics 2015-06-24 A. A. Coley

The Raychaudhuri equations for the expansion, shear and vorticity are generalized in a spacetime with torsion for timelike as well as null congruences. These equations are purely geometrical like the original Raychaudhuri equations and…

General Relativity and Quantum Cosmology · Physics 2021-10-27 Sudipta Hensh , Stefano Liberati

We look for a Brans-Dicke type of generalization of the Horava-Lifshitz gravity. It is shown that such a generalization is possible within the detailed balance condition. Classically, the resulting theory reduces in the IR limit to the…

High Energy Physics - Theory · Physics 2015-05-18 Joohan Lee , Tae Hoon Lee , Phillial Oh

The equivalence between f(R) gravity and scalar-tensor theories is invoked to study the null, strong, weak and dominant energy conditions in Brans-Dicke theory. We consider the validity of the energy conditions in Brans-Dicke theory by…

General Relativity and Quantum Cosmology · Physics 2009-08-25 K. Atazadeh , A. Khaleghi , H. R. Sepangi , Y. Tavakoli

We consider spacetimes consisting of a manifold with Lorentzian metric and a weight function or scalar field. These spacetimes admit a Bakry-\'Emery-Ricci tensor which is a natural generalization of the Ricci tensor. We impose an energy…

Differential Geometry · Mathematics 2015-10-28 Gregory J. Galloway , Eric Woolgar

We present the complete solution to the classification problem regarding the variational symmetries of the generalized Brans-Dicke cosmological model in the presence of a second scalar field minimally coupled to gravity and the generalized…

General Relativity and Quantum Cosmology · Physics 2024-12-25 Andronikos Paliathanasis

We investigate the geodesic deviation equation in the context of quantum improved spacetimes. The improved Raychaudhuri equation is derived, and it is shown that the classical strong energy condition does not necessarily lead to the…

General Relativity and Quantum Cosmology · Physics 2020-03-11 R. Moti , A. Shojai

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

We consider an extended scalar-tensor theory of gravity where the action has two interacting scalar fields, a Brans-Dicke field which makes the effective Newtonian constant a function of coordinates and a Higgs field which has derivative…

General Relativity and Quantum Cosmology · Physics 2021-01-13 Soumya Chakrabarti

In this review, we provide a concrete overview of the Raychaudhuri equation, Focusing theorem and Convergence conditions in a plethora of backgrounds and discuss the consequences. We also present various classical and quantum approaches…

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

We discuss two spherically symmetric solutions admitted by the Horndeski (or scalar tensor) theory in the context of solar system and astrophysical scenarios. One of these solutions is derived for Einstein-Gauss-Bonnet gravity, while the…

General Relativity and Quantum Cosmology · Physics 2017-02-28 Sourav Bhattacharya , Sumanta Chakraborty