Singularities and Entropy in Bulk Viscosity Dark Energy Model

• 作者: 孟新河 窦旭
• 来源期刊: 理论物理通讯：英文版
• 学科: 工学
• 关键词: 粘度模型 能量模型 奇异性 散装 宇宙演化 熵 清洁发展机制 时间箭头
• 年，卷（期）: 2011,（11）
• 页码范围: 957-966
• 页数: 10页
• 分类号: O414.1|TQ320.662
• 语种: 英文

摘要

In this paper bulk viscosity is introduced to describe the effects of cosmic non-perfect fluid on the cosmos evolution and to build the unified dark energy （DE） with （dark） matter models. Also we derive a general relation between the bulk viscosity form and Hubble parameter that can provide a procedure for the viscosity DE model building. Especially, a redshift dependent viscosity parameter ζ ∝ λ0 ＋λ1（1 ＋z）n proposed in the previous work [X.H. Meng and X. Dou, Commun. Theor. Phys. B2 （2009） 377] is investigated extensively in this present work. Further more we use the recently released supernova dataset （the Constitution dataset） to constrain the model parameters. In order to differentiate the proposed concrete dark energy models from the well known ACDM model, statefinder diagnostic method is applied to this bulk viscosity model, as a complementary to the Om parameter diagnostic and the deceleration parameter analysis performed by us before. The DE model evolution behavior and tendency are shown in the plane of the statefinder diagnostic parameter pair {τ, s} as axes where the fixed point represents the A CDM model The possible singularity property in this bulk viscosity cosmology is also discussed to which we can conclude that in the different parameter regions chosen properly, this concrete viscosity DE model can have various late evolution behaviors and the late time singularity could be avoided. We also calculate the cosmic entropy in the bulk viscosity dark energy frame, and find that the total entropy in the viscosity DE model increases monotonously with respect to the scale factor evolution, thus this monotonous increasing property can indicate an arrow of time in the universe evolution, though the quantum version of the arrow of time is still very puzzling.

作者信息

序号	姓名	单位	发文数	被引次数	H指数	G指数
1	孟新河		5	0	0.0	0.0
2	窦旭		1	0	0.0	0.0