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Related papers: Vaidya Spacetime in Brans-Dicke Gravity's Rainbow

200 papers

We discuss the dynamics of a spherically symmetric dark radiation vaccum in the Randall-Sundrum brane world scenario. Under certain natural assumptions we show that the Einstein equations on the brane form a closed system. For a de Sitter…

High Energy Physics - Theory · Physics 2017-08-23 Rui Neves , Cenalo Vaz

We examine the role of space-time geometry in the non-adiabatic collapse of a star dissipating energy in the form of radial heat flow, studying its evolution under different initial conditions. The collapse of a star with interior…

General Relativity and Quantum Cosmology · Physics 2013-04-30 R. Sharma , R. Tikekar

In this work, we explore the possibility that quantum fluctuations induce a topology change, in the context of Gravity's Rainbow. A semi-classical approach is adopted, where the graviton one-loop contribution to a classical energy in a…

General Relativity and Quantum Cosmology · Physics 2014-08-21 Remo Garattini , Francisco S. N. Lobo

We calculate deviations in cosmological observables as a function of parameters in a class of connection-based models of quantum gravity. In this theory non-trivial modifications to the background cosmology can occur due to a distortion of…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-01 Michael W. Toomey , Savvas Koushiappas , Bruno Alexandre , João Magueijo

The aim of this work is to formulate two new solutions by decoupling the field equations via a minimal geometric deformation in the context of self-interacting Brans-Dicke gravity. We introduce an extra source in the anisotropic fluid…

General Relativity and Quantum Cosmology · Physics 2022-01-14 M. Sharif , Amal Majid

We discuss possible tests of the constancy of the velocity of light using distant astrophysical sources such as gamma-ray bursters (GRBs), Active Galactic Nuclei (AGNs) and pulsars. This speculative quest may be motivated by some models of…

Astrophysics · Physics 2008-11-26 J. Ellis , K. Farakos , N. E. Mavromatos , V. Mitsou , D. V. Nanopoulos

In some models of quantum gravity, space-time is thought to have a foamy structure with non-trivial optical properties. We probe the possibility that photons propagating in vacuum may exhibit a non-trivial refractive index, by analyzing the…

Astrophysics · Physics 2008-11-26 J. Ellis , N. E. Mavromatos , D. V. Nanopoulos , A. S. Sakharov

The emergence of the quantum gravitational effects in a very high energy regime necessitates some corrections to the thermodynamics of Black holes. In this letter, we investigate a possible modification to the thermodynamics of…

General Relativity and Quantum Cosmology · Physics 2015-09-30 Akram Sadat Sefiedgar

This paper investigates instability ranges of a cylindrically symmetric collapsing stellar object in Brans-Dicke theory of gravity. For this purpose, we use perturbation approach in the modified field equations as well as dynamical…

General Relativity and Quantum Cosmology · Physics 2016-07-20 M. Sharif , Rubab Manzoor

A Vaidya spacetime is considered for gravitational collapse of a type II fluid in the context of Rastall theory of gravity. For a linear equation of state (EoS) for the fluid profiles, the conditions under which the dynamical evolution of…

General Relativity and Quantum Cosmology · Physics 2020-09-11 Amir H. Ziaie , Yaser Tavakoli

We derive a set of equations describing the linear response of the convergence properties of a geodesic congruence to arbitrary geometry variations. It is a combination of equations describing the deviations from the standard…

General Relativity and Quantum Cosmology · Physics 2015-09-14 Masafumi Seriu

The gravitational collapse of a high-density null charged matter fluid, satisfying the Hagedorn equation of state, is considered in the framework of the Vaidya geometry. The general solution of the gravitational field equations can be…

General Relativity and Quantum Cosmology · Physics 2009-11-10 T. Harko

In this paper, we study Friedmann cosmology with time-varying vacuum energy density in the context of Brans-Dicke theory. We consider an isotropic and homogeneous flat space, filled with a matter-dominated perfect fluid and a dynamical…

General Relativity and Quantum Cosmology · Physics 2024-01-09 C. P. Singh , Joan Sola Peracaula

The degree of freedom of the scalar field in scalar-tensor gravity is employed as "time" to deparametrize the Hamiltonian constraint of the theory. The deparametrized system is then nonperturbatively quantized by the approach of loop…

General Relativity and Quantum Cosmology · Physics 2026-03-02 Faqiang Yuan , Haida Li , Shengzhi Li , Yongge Ma

The process of the gravitational collapse might lead not only to a black hole but also to naked singularity formation. In this paper, we consider the generalized Vaidya spacetime with polytropic and generalized polytropic equations of…

General Relativity and Quantum Cosmology · Physics 2024-02-27 Vitalii Vertogradov

In this work, we study the three-dimensional AdS gravitational vacuum stars (gravastars) in the context of gravity's rainbow theory. Then we extend it by adding the Maxwell electromagnetic field. We compute the physical features of…

General Relativity and Quantum Cosmology · Physics 2023-02-17 H. Barzegar , M. Bigdeli , G. H. Bordbar , B. Eslam Panah

In this paper, we consider the spherically symmetric gravitational collapse of isotropic matter undergoing dissipation in the form of heat flux, with a generalized Vaidya exterior, in the context of $f(R, T)$ gravity. Choosing $f(R,…

General Relativity and Quantum Cosmology · Physics 2025-08-11 Uttaran Ghosh , Sarbari Guha

We consider a gravitational model in a Weyl-Cartan space-time, in which the Weitzenb\"{o}ck condition of the vanishing of the sum of the curvature and torsion scalar is also imposed. Moreover, a kinetic term for the torsion is also included…

General Relativity and Quantum Cosmology · Physics 2013-08-13 Zahra Haghani , Tiberiu Harko , Hamid Reza Sepangi , Shahab Shahidi

In this paper we generalise core-envelope model of superdense star to a non-commutative space-time and study the modifications due to the existence of a minimal length, predicted by various approaches to quantum gravity. We first derive…

General Relativity and Quantum Cosmology · Physics 2019-05-13 Bhanu Kiran. S , E. Harikumar , Vishnu Rajagopal

The $ \gamma $-spacetime metric is a static and axially symmetric vacuum solution of the Einstein equation. This spacetime represents a naked singularity and it has an extra parameter $ \gamma $ which signifies deviations from spherical…

General Relativity and Quantum Cosmology · Physics 2023-11-21 Hrishikesh Chakrabarty , Yong Tang