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Indexed by:期刊论文

Date of Publication:2013-06-01

Journal:EUROPEAN PHYSICAL JOURNAL C

Included Journals:SCIE、Scopus

Volume:73

Issue:6

Page Number:1-7

ISSN No.:1434-6044

Abstract:In this paper, we revisit viscous generalized Chaplygin gas (VGCG) as a unified dark fluid, which modifies the pressure only by redefining the effective pressure p(eff), according to p(eff) = p - root 3 zeta(0)rho, where zeta(0) is the newly added model parameter which characterizes the viscous property and can be determined by the cosmic observations. By using the currently available cosmic observational data from WMAP, BAO, and SN Ia, the model parameter space is obtained via a Markov Chain Monte Carlo method: zeta(0) = 0.000708(-0.00155-0.00311-0.00503)(+0.00151+0.00275+0.00425) in 1, 2, 3 sigma regions. The results show that the viscous effect is very small due the value zeta(0) approximate to 0 and the VGCG model can match observational data points as well as Lambda CDM model.