Exact analytical solution for an Israel–Stewart cosmology
Exact analytical solution for an Israel–Stewart cosmology
复制标题
以色列-斯图尔特宇宙学的精确解析解
DOI：
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
G. Palma
中科院分区：
文献类型：
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作者：
N. Cruz;E. González;G. Palma
在这篇文章中，我们报告了一个新的分析解决方案，描述了一个宇宙学模型的物质含量由一个耗散流体组件，在因果的以色列-斯图尔特理论的框架。耗散流体用正压状态方程p=（gamma-1）描述
ho $$ p =（γ - 1）ρ，并且本体粘度假定为$$xi =xi _{0}的形式
ho ^{s}$$= 0 ρ s。我们研究的参数空间内的标签的解决方案，一个合适的区域兼容的宇宙加速膨胀的后期，以及稳定性的解决方案在临界参数值$$伽玛= 1$$ γ = 1和$$ s = 1/2 $$ s = 1 / 2。我们还研究了沿着时间的演化，熵产生的积极性所产生的后果。我们发现，无压暗物质的解，$$ gamma = 1$$ γ = 1，可以很好地描述宇宙从减速膨胀到后期加速膨胀的过渡，但对声速有很大的非绝热贡献。最后，从膨胀类型和熵产生的角度讨论了解的运动学和热力学性质。
In this article we report a novel analytic solution describing a cosmological model with a matter content represented by a one dissipative fluid component, in the framework of the causal Israel–Stewart theory. The dissipative fluid is described by a barotropic equation of state $$p= (gamma -1)
ho $$ p = ( γ - 1 ) ρ and the bulk viscosity has been assumed of the form $$xi =xi _{0}
ho ^{s}$$ ξ = ξ 0 ρ s . We study within the parameter space which label the solution, a suited region compatible with an accelerated expansion of the universe for late times, as well as stability properties of the solution at the critical parameter value $$ gamma = 1$$ γ = 1 and for $$ s = 1/2 $$ s = 1 / 2 . We study as well the consequences that arise from the positiveness of the entropy production along the time evolution. We found that the solution for pressureless dark matter, $$ gamma = 1$$ γ = 1 , can well describe a universe with a transition from a decelerated expansion to an accelerated one at late times, but with a very large non-adiabatic contribution to speed of sound. Finally, the kinematics and thermodynamics properties of the solutions are discussed in terms of the type of expansion and entropy production.