Energy conditions and entropy density of the universe. (arXiv:1009.4513v2 [astro-ph.CO] UPDATED)

<a href="http://arxiv.org/find/astro-ph/1/au:+Liu_W/0/1/0/all/0/1">Wen-Fei Liu</a> (1 and 2), <a href="http://arxiv.org/find/astro-ph/1/au:+Niu_J/0/1/0/all/0/1">Jing Niu</a> (2), <a href="http://arxiv.org/find/astro-ph/1/au:+Li_J/0/1/0/all/0/1">Juan Li</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_T/0/1/0/all/0/1">Tong-Jie Zhang</a> (2) ((1) College of Physics and Electronic Engineering, Qilu Normal University,(2) Department of Astronomy, Beijing Normal University)

In the standard Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmological

model, the energy conditions provides model-independent bounds on the behavior

of the distance modulus. However, this method can not provide us the detailed

information about the violation between the energy conditions and the

observation. In this paper, we present an extended analysis of the energy

conditions based upon the entropy density of the universe. On the one hand, we

find that these conditions imply that entropy density s depends on Hubble

parameter H(z). On the other hand, we compare the theoretical entropy density

from the conservation law of energy-momentum tensor with that from the energy

conditions using the observational Hubble parameter. When we consider a FLRW

universe, according to the theoretical prediction, OHD, thermodynamics and

several independent cosmological probes, show that the dominant energy

condition is fitter than other energy conditions.

In the standard Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmological

model, the energy conditions provides model-independent bounds on the behavior

of the distance modulus. However, this method can not provide us the detailed

information about the violation between the energy conditions and the

observation. In this paper, we present an extended analysis of the energy

conditions based upon the entropy density of the universe. On the one hand, we

find that these conditions imply that entropy density s depends on Hubble

parameter H(z). On the other hand, we compare the theoretical entropy density

from the conservation law of energy-momentum tensor with that from the energy

conditions using the observational Hubble parameter. When we consider a FLRW

universe, according to the theoretical prediction, OHD, thermodynamics and

several independent cosmological probes, show that the dominant energy

condition is fitter than other energy conditions.

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