约束一个因果耗散宇宙模型
Constraining a causal dissipative cosmological model
摘要：
本文利用哈勃参数（OHD）和Ia型超新星（SNIa）的最新测量结果，给出了Isarel-Stewart因果近似的多项式型$H \approx ( t + const.)^{-1}$宇宙学解（见\cite{MCruz:2017, Cruz2017}）。由于这个解所描述的膨胀并不存在从减速相到加速相的过渡，因此通过要求哈勃参数在$z=z_{t}$（加速-减速过渡红移）处的连续性，可以很好地模拟这两个相。我们的最佳拟合约束模型的主要自由参数为加速（减速）阶段的$A_1= 1.58^{+0.08}_{-0.07}$（$A_2=0.84^{+0.02}_{-0.02}$）。对于这两个阶段，我们得到$q=-0.37^{+0.03}_{-0.03}$（$0.19^{+0.03}_{-0.03}$）和$ω_{eff} = -0.58^{+0.02}_{-0.02}$（$-0.21^{+0.02}_{-0.02}$）的减速参数和有效的状态方程，分别。通过Akaike信息准则和Bayesian信息准则对LCDM模型和OHD+SNIa数据进行统计比较，得出LCDM模型更适合OHD+SNIa数据。最后，它示出的约束参数值满足一致的流体描述的耗散暗物质成分的标准，但具有高值的流体内的声音的声速，这是一个缺点的结构形成的一致的描述。我们简要地讨论了克服这个问题的可能性与非线性概括的因果线性热力学的体积粘度，也与列入某种形式的暗能量。
英文摘要：
In this paper a cosmological solution of polynomial type $H \approx ( t + const.)^{-1}$ for the causal thermodynamical approach of Isarel-Stewart, found in \cite{MCruz:2017, Cruz2017}, is constrained using the joint of the latest measurements of the Hubble parameter (OHD) and Type Ia Supernovae (SNIa). Since the expansion described by this solution does not present a transition from a decelerated phase to an accelerated one, both phases can be well modeled connecting both phases by requiring the continuity of the Hubble parameter at $z=z_{t}$, the accelerated-decelerated transition redshift. Our best fit constrains the main free parameters of the model to be $A_1= 1.58^{+0.08}_{-0.07}$ ($A_2=0.84^{+0.02}_{-0.02}$) for the accelerated (decelerated) phase. For both phases we obtain $q=-0.37^{+0.03}_{-0.03}$ ($0.19^{+0.03}_{-0.03}$) and $ω_{eff} = -0.58^{+0.02}_{-0.02}$ ($-0.21^{+0.02}_{-0.02}$) for the deceleration parameter and the effective equation of state, respectively. Comparing our model and LCDM statistically through the Akaike information criterion and the Bayesian information criterion we obtain that the LCDM model is preferred by the OHD+SNIa data. Finally, it is shown that the constrained parameters values satisfy the criterion for a consistent fluid description of a dissipative dark matter component, but with a high value of the speed of sound within the fluid, which is a drawback for a consistent description of the structure formation. We briefly discuss the possibilities to overcome this problem with a non-linear generalization of the causal linear thermodynamics of bulk viscosity and also with the inclusion of some form of dark energy.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
