A Modified Generalized Chaplygin Gas as the Unified Dark Matter-Dark Energy Revisited

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	A Modified Generalized Chaplygin Gas as the Unified Dark Matter-Dark Energy Revisited
	Deng, Xue-Mei
刊名	BRAZILIAN JOURNAL OF PHYSICS
	2011-12-01
卷号	41 期号:4-6 页码:333-348
关键词	Dark energy Dark matter
ISSN号	0103-9733
英文摘要	A modified generalized Chaplygin gas (MGCG) is considered as the unified dark matter-dark energy revisited. The character of MGCG is endued with the dual role, which behaves as matter at early times and as a quiessence dark energy at late times. The equation of state for MGCG is p = -alpha rho/(1 + alpha) - nu(z)rho(-alpha)/(1 + alpha), where nu(z) = -[rho(0c)(1 + z)(3)]((1 + alpha))(1 - Omega(0B))(alpha) {alpha Omega(0DM) + Omega(0DE)[omega(DE) + alpha(1 + omega(DE))](1 + z)3(omega DE(1+alpha))}. Some cosmological quantities, such as the densities of different components of the universe Omega(i) (i, respectively, denotes baryons, dark matter, and dark energy) and the deceleration parameter q, are obtained. The present deceleration parameter q(0), the transition redshift z(T), and the redshift z(eq), which describes the epoch when the densities in dark matter and dark energy are equal, are also calculated. To distinguish MGCG from others, we then apply the Statefinder diagnostic. Later on, the parameters (alpha and omega(DE)) of MGCG are constrained by combination of the sound speed c(s)(2), the age of the universe t(0), the growth factor m, and the bias parameter b. It yields alpha = -3.07(-4.98)(+5.66) x 10(-2) and omega(DE) = -1.05(-0.11)(+0.06). Through the analysis of the growth of density perturbations for MGCG, it is found that the energy will transfer from dark matter to dark energy which reach equal at z(eq) similar to 0.48 and the density fluctuations start deviating from the linear behavior at z similar to 0.25 caused by the dominance of dark energy.
学科主题	Physics
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Physics, Multidisciplinary
研究领域[WOS]	Physics
关键词[WOS]	PROBE WMAP OBSERVATIONS ; GALAXY REDSHIFT SURVEY ; GLOBULAR-CLUSTER MESSIER-4 ; HUBBLE-SPACE-TELESCOPE ; EQUATION-OF-STATE ; COSMOLOGICAL CONSTANT ; UNIVERSE ; CONSTRAINTS ; SUPERNOVAE ; STATEFINDER
收录类别	SCI
语种	英语
WOS记录号	WOS:000296782900015
公开日期	2012-08-07
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/4458]
专题	紫金山天文台_历算和天文参考系研究团组
作者单位	Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Peoples R China
推荐引用方式 GB/T 7714	Deng, Xue-Mei. A Modified Generalized Chaplygin Gas as the Unified Dark Matter-Dark Energy Revisited[J]. BRAZILIAN JOURNAL OF PHYSICS,2011,41(4-6):333-348.
APA	Deng, Xue-Mei.(2011).A Modified Generalized Chaplygin Gas as the Unified Dark Matter-Dark Energy Revisited.BRAZILIAN JOURNAL OF PHYSICS,41(4-6),333-348.
MLA	Deng, Xue-Mei."A Modified Generalized Chaplygin Gas as the Unified Dark Matter-Dark Energy Revisited".BRAZILIAN JOURNAL OF PHYSICS 41.4-6(2011):333-348.