论文标题
遗赠深色流体：观察性和热力学约束
The Logotropic Dark Fluid: Observational and Thermodynamic Constraints
论文作者
论文摘要
我们已经考虑了一个空间平坦，均质和各向同性的FLRW宇宙，充满了单个流体，称为逻辑深色液体（LDF），其压力通过状态的对数方程而演变。我们使用最近的Pantheon SNIA和COSMIC CERMONER数据集来限制此模型的参数，深色物质的当前部分$ω__{M0} $和HUBBLE常数$ H_0 $。我们发现，这些参数的平均值为$ω_{M0} = 0.288 \ pm 0.012 $和$ h_ {0} = 69.652 \ pm 1.698〜 {\ rm km/s/s/s/mpc} $ at $1σ$ Cl。我们还发现，LDF模型在最近的过去显示了从减速阶段到宇宙加速阶段的平稳过渡。我们注意到，此过渡$ z_ {t} = 0.706 \ pm 0.048 $（$1σ$错误）的红移，并且与当前的观测值一致。有趣的是，我们发现宇宙将来会定位为$λ$ CDM的模型，而LDF模型将来不会有任何奇异性。此外，我们注意到当前时期的LDF和$λ$ CDM模型之间没有显着差异，但是随着红移的增加，这些模型之间的差异（在百分比级别）之间存在差异。我们还研究了使用Bekenstein和Viaggiu熵的LDF模型在动力学明显范围内的热力学第二定律。
We have considered a spatially flat, homogeneous and isotropic FLRW Universe filled with a single fluid, known as logotropic dark fluid (LDF), whose pressure evolves through a logarithmic equation of state. We use the recent Pantheon SNIa and cosmic chronometer datasets to constrain the parameters of this model, the present fraction of dark matter $Ω_{m0}$ and the Hubble constant $H_0$. We find that the mean values of these parameters are $Ω_{m0}=0.288\pm 0.012$ and $H_{0}=69.652\pm 1.698~{\rm km/s/Mpc}$ at the $1σ$ CL. We also find that the LDF model shows a smooth transition from the deceleration phase to acceleration phase of the universe in the recent past. We notice that the redshift of this transition $z_{t}=0.706\pm 0.048$ ($1σ$ error) and is well consistent with the present observations. Interestingly, we find that the Universe will settle down to a $Λ$CDM model in future and there will not be any future singularity in the LDF model. Furthermore, we notice that there is no significant difference between the LDF and $Λ$CDM models at the present epoch, but the difference (at the percent level) between these models is found as the redshift increases. We have also studied the generalized second law of thermodynamics at the dynamical apparent horizon for the LDF model with the Bekenstein and Viaggiu entropies.
