English
Related papers

Related papers: Brans-Dicke Cosmology: Thermodynamic viability

200 papers

This work is to study the generalized second law (GSL) of thermodynamics in tachyon cosmology where the boundary of the universe is assumed to be enclosed by a dynamical apparent horizon. The model is constrained with the observational…

General Relativity and Quantum Cosmology · Physics 2016-06-08 H. Farajollahi , A. Ravanpak , H. Shojaie , M. Abolghasemi

We study longstanding problem of cosmological clock in the context of Brans-Dicke theory of gravitation. We present the Hamiltonian formulation of the theory for a class of spatially homogenous cosmological models. Then, we show that…

General Relativity and Quantum Cosmology · Physics 2011-06-09 Hossein Farajollahi , Mehrdad Farhoudi , Hossein Shojaie

In this letter, we investigate the validity of the generalized second law of thermodynamics of the universe bounded by the event horizon in the holographic dark energy model. The universe is chosen to be homogeneous and isotropic and the…

General Relativity and Quantum Cosmology · Physics 2010-11-04 Nairwita Mazumder , Subenoy Chakraborty

The first and second laws of thermodynamics should lead to a consistent scenario for discussing the cosmological constant problem. In the present study, to establish such a thermodynamic scenario, cosmological equations in a flat…

General Relativity and Quantum Cosmology · Physics 2025-06-05 Nobuyoshi Komatsu

Homogeneous and isotropic, nonsingular, bouncing world models are designed to evade the initial singularity at the beginning of the cosmic expansion. Here, we study the thermodynamics of the subset of these models governed by general…

General Relativity and Quantum Cosmology · Physics 2016-03-09 Pedro C. Ferreira , Diego Pavon

We derive the generalized Friedmann equation governing the cosmological evolution inside the thick brane model in the presence of two curvature correction terms: a four-dimensional scalar curvature from induced gravity on the brane, and a…

High Energy Physics - Theory · Physics 2014-11-18 Shao-Feng Wu , Guo-Hong Yang , Peng-Ming Zhang

In this work, we have described the Brans-Dicke theory of gravity and given a particular solution by choosing a power law form of scalar field $\phi$ and constant $\omega$. If we assume first law and entropy formula on apparent horizon then…

General Relativity and Quantum Cosmology · Physics 2015-05-19 Samarpita Bhattacharya , Ujjal Debnath

In this paper, we obtain exact cosmological vacuum solutions for an extended FLRW homogenous and isotropic Brans-Dicke (BD) universe in five dimensions for all values of the curvature index. Then, by employing the equations associated to a…

General Relativity and Quantum Cosmology · Physics 2016-07-05 S. M. M. Rasouli , Paulo Vargas Moniz

We consider Brans-Dicke theory with a self-interacting potential in Einstein conformal frame. We introduce a class of solutions in which an accelerating expansion is possible in a spatially flat universe for positive and large values of the…

General Relativity and Quantum Cosmology · Physics 2012-05-03 Yousef Bisabr

We investigate the validity of the generalized second law (GSL) of gravitational thermodynamics in the framework of f(T) modified teleparallel gravity. We consider a spatially flat FRW universe containing only the pressureless matter. The…

General Relativity and Quantum Cosmology · Physics 2012-04-12 K. Karami , A. Abdolmaleki

Modified gravity and generalized second law (GSL) of thermodynamics are interesting topics in the modern cosmology. In this regard, we investigate the GSL of gravitational thermodynamics in the framework of modified Gauss-Bonnet gravity or…

General Relativity and Quantum Cosmology · Physics 2016-11-22 A. Abdolmaleki , T. Najafi

In the previous analyses in the literature about the generalized second law (GSL) in an accelerated expanding universe the usual area relation for the entropy, i.e. $S={A\over 4G}$, was used for the cosmological horizon entropy. But this…

General Relativity and Quantum Cosmology · Physics 2011-01-14 H. Mohseni Sadjadi , Mubasher Jamil

Brans-Dicke (BD) cosmology is reconsidered from an approach in which the model can be formulated in $\Lambda$CDM form, but at the expense of replacing the rigid cosmological constant $\Lambda$ with a dynamical quasivacuum component which…

General Relativity and Quantum Cosmology · Physics 2018-11-29 Javier de Cruz Perez , Joan Sola

Inhomogeneous multidimensional cosmological models with a higher dimensional space-time manifold M= M_0 x M_1 ...x M_n are investigated under dimensional reduction to a D_0-dimensional effective non-minimally coupled sigma-model which…

General Relativity and Quantum Cosmology · Physics 2015-06-25 M. Rainer , A. Zhuk

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

Here, we study the generalized second law (GSL) of thermodynamics in the framework of massive gravity. To do this, we consider a FRW universe filled only with matter and enclosed by the apparent horizon. In addition, we consider two models…

General Relativity and Quantum Cosmology · Physics 2024-03-01 Mohammad Beigmohammadi , Kayoomars Karami

In this work, we have considered the power law correction of entropy on the horizon. If the flat FRW Universe is filled with the n components fluid with interactions, the GSL of thermodynamics for apparent and event horizons have been…

General Relativity and Quantum Cosmology · Physics 2012-07-03 Ujjal Debnath , Surajit Chattopadhyay , Ibrar Hussain , Mubasher Jamil , Ratbay Myrzakulov

In this work, we have investigated the validity of the generalized second law of thermodynamics in logamediate and intermediate scenarios of the universe bounded by the Hubble, apparent, particle and event horizons using and without using…

General Physics · Physics 2012-01-25 Arundhati Das , Surajit Chattopadhyay , Ujjal Debnath

A classical and quantum mechanical generalized second law of thermodynamics in cosmology implies constraints on the effective equation of state of the universe in the form of energy conditions, obeyed by many known cosmological solutions,…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Ram Brustein

A study of Universal thermodynamics is done in the frame work of RSII brane model and DGP brane scenario. The Universe is chosen as FRW model bounded by apparent or event horizon. Assuming extended Hawking temperature on the horizon, the…

General Relativity and Quantum Cosmology · Physics 2016-05-17 Saugata Mitra , Subhajit Saha , Subenoy Chakraborty