Generalized second law of thermodynamics in the emergent universe for some viable models of f(T) gravity

Rahul Ghosh; Antonio Pasqua; Surajit Chattopadhyay

doi:10.1140/epjp/i2013-13012-6

EPJ

Generalized second law of thermodynamics in the emergent universe for some viable models of f(T) gravity

Rahul Ghosh¹^*, Antonio Pasqua² and Surajit Chattopadhyay³

¹ Department of Mathematics, Bhairab Ganguly College, 700 056, Kolkata, India
² Department of Physics, University of Trieste, Via Valerio, 234127, Trieste, Italy
³ Pailan College of Management and Technology, Bengal Pailan Park, 700 104, Kolkata, India

Received: 15 July 2012
Revised: 12 January 2013
Accepted: 15 January 2013
Published online: 5 February 2013

Abstract

The present work is motivated by the study of the paper K. Karami, A. Abdolmaleki, J. Cosmol. Astropart. Phys. 04, 007 (2012), where the generalized second law (GSL) of thermodynamics has been investigated for a flat FRW universe for three viable models of f(T) gravity. We have here considered a non-flat universe and, accordingly, studied the behaviors of the equation-of-state (EoS) parameter ω and of the deceleration parameter q. Subsequently, using the first law of thermodynamics, we derived the expressions for the time derivative of the total entropy of a universe enveloped by apparent horizon. In the next phase, with the choice of scale factor a(t) pertaining to an emergent universe, we have investigated the sign of the time derivatives of total entropy for the models of f(T) gravity considered.