corner
corner

Phys. Rev. D 74, 083520 (2006) [7 pages]

Thermodynamics of an accelerated expanding universe

Download: PDF (170 kB) Buy this article Export: BibTeX or EndNote (RIS)

Bin Wang*
Department of Physics, Fudan University, Shanghai 200433, People’s Republic of China

Yungui Gong
Institute of Modern Physics and College of Electronic Engineering, Chongqing University of Posts and Telecommunications, Chongqing 400065, China

Elcio Abdalla
Instituto de Fisica, Universidade de Sao Paulo, C.P.66.318, CEP 05315-970, Sao Paulo, Brazil

Received 5 June 2006; published 27 October 2006

We investigate the laws of thermodynamics in an accelerating universe driven by dark energy with a time-dependent equation of state. In the case we consider that the physically relevant part of the Universe is that enveloped by the dynamical apparent horizon, we have shown that both the first law and second law of thermodynamics are satisfied. On the other hand, if the boundary of the Universe is considered to be the cosmological event horizon the thermodynamical description based on the definitions of boundary entropy and temperature breaks down. No parameter redefinition can rescue the thermodynamics laws from such a fate, rendering the cosmological event horizon unphysical from the point of view of the laws of thermodynamics.

© 2006 The American Physical Society

URL:
http://link.aps.org/doi/10.1103/PhysRevD.74.083520
DOI:
10.1103/PhysRevD.74.083520
PACS:
98.80.Cq, 98.80.−k

*Electronic address: wangb@fudan.edu.cn

Electronic address: gongyg@cqupt.edu.cn

Electronic address: eabdalla@fma.if.usp.br