论文标题
关于在晚期加速的情况下截断以色列 - 斯图尔特模型的可行性
On the feasibility of truncated Israel-Stewart model in the context of late acceleration
论文作者
论文摘要
基于因果关系截断以色列 - 斯图尔特理论的宇宙的耗散模型，在宇宙最近加速扩张的背景下进行了分析。散装粘度和放松时间分别为$ξ=αρ^s $和$τ= \fracα{εγ（2-γ）}ρ^{s-1} $。对于$ s = 1/2，$我们找到了模型哈勃参数的分析解决方案。我们已经使用最新的宇宙学数据将$γ= 1 $和$γ$处理为免费参数来估计模型参数。 该模型可以预测与标准$λ$ CDM模型中的先前减速相位和最终de Sitter相。动力学系统分析表明，先前的减速时期是一个不稳定的平衡，而遥远的未来的自在时期是稳定的。宇宙的年龄获得了$ 13.66 $ GYR，这与最近的观察结果接近。在该模型的整个演变中，发现热力学的第二定律可以满足。该模型的可行性已与基于以色列完整的模型和ECKART粘性理论进行对比。截断的粘性模型似乎与天文观测更兼容，而不是ECKART和完整的因果粘性模型。
A dissipative model of the Universe based on the causal relativistic truncated Israel-Stewart theory is analysed in the context of recent accelerated expansion of the Universe. The bulk viscosity and relaxation time are taken as $ξ=αρ^s$ and $τ=\fracα{εγ(2-γ)}ρ^{s-1}$ respectively. For $s=1/2,$ we found an analytical solution for the Hubble parameter of the model. We have estimated the model parameters by treating $γ=1$ and $γ$ as a free parameter using the latest cosmological data. The model predicts a prior decelerated phase and an end de Sitter phase as in the standard $Λ$CDM model. The dynamical system analysis shows that the prior decelerated epoch is an unstable equilibrium, while the far future de Sitter epoch is stable. The age of the Universe obtained around $13.66$ Gyr, which is close to the recent observations. The second law of thermodynamics is found to be satisfied throughout the evolution in this model. The feasibility of the model has been checked by contrasting with models based on the full Israel-Stewart and the Eckart viscous theories. The truncated viscous model appears more compatible with astronomical observations than the Eckart and full causal viscous models.
