English

Thermodynamics in $f(R,R_{\alpha\beta}R^{\alpha\beta},\phi)$ theory of gravity

General Relativity and Quantum Cosmology 2016-11-17 v2

Abstract

First and second laws of black hole thermodynamics are examined at the apparent horizon of FRW spacetime in f(R,RαβRαβ,ϕ)f(R,R_{\alpha\beta}R^{\alpha\beta} ,\phi) gravity, where RR, RαβRαβR_{\alpha\beta}R^{\alpha\beta} and ϕ\phi are the Ricci scalar, Ricci invariant and the scalar field respectively. In this modified theory, Friedmann equations are formulated for any spatial curvature. These equations can be presented into the form of first law of thermodynamics for ThdS^h+ThdiS^h+WdV=dET_{h}d\hat{S}_{h}+ T_{h}d_{i}\hat{S}_{h}+W dV=dE, where diS^hd_{i}\hat{S}_{h} is an extra entropy term because of the non-equilibrium presentation of the equations and ThdS^h+WdV=dET_{h}d\hat{S}_{h}+W dV=dE for the equilibrium presentation. The generalized second law of thermodynamics (GSLT) is expressed in an inclusive form where these results can be represented in GR f(R)f(R) and f(R,ϕ)f(R, \phi) gravities. Finally to check the validity of GSLT, we take some particular models and produce constraints of the parameters.

Keywords

Cite

@article{arxiv.1604.07213,
  title  = {Thermodynamics in $f(R,R_{\alpha\beta}R^{\alpha\beta},\phi)$ theory of gravity},
  author = {M. Zubair and Farzana Kousar and Sebastian Bahamonde},
  journal= {arXiv preprint arXiv:1604.07213},
  year   = {2016}
}

Comments

29 pages, 4 figures