论文标题
宇宙学观察对多组分暗能量的限制
Constraints on Multicomponent Dark Energy from Cosmological Observations
论文作者
论文摘要
暗能量（de）在我们宇宙的扩张历史中起着重要作用。但是，几十年来，我们只有对其性质和特性的知识有限。在大多数数值研究中，DE通常被视为动态整体。实际上，多组分DE模型还可以解释我们宇宙的加速扩展，从理论上讲，这是被接受的，但缺乏数值研究。我们尝试通过构建$ W_N $ CDM型号来研究观察模型的多组分DE模型。 DE的总能量密度分为$ n $（$ n = 2,3,5 $），并且每个零件都具有恒定的EOS $ W_I $（$ i = 1,2 ... n $）。我们修改了Friedmann方程和DE的参数化邮政涂料描述，然后对Planck 2018 TT，TE，EE $+$ LOWE $+$+$ lensing，Bao Data和Pantheon Samples的$ W_I $ S放大。如果观察数据优先考虑任何$ W_N $ CDM模型，并且在$ W_I $ s的最高值和最低值之间没有重叠的重叠，那么多组件DE模型将受到青睐。当$ n $很小时，我们发现数据组合支持$ W_N $ CDM模型，并且$ W_2 $ CDM模型略微优先，$Δχ^2 _ {\ text {min}} =δ\ text {aic} =δ} =δ使用较大的$ n $，最大值和最小值的$ w_i $ s不会彼此重叠，而是$χ^2 _ {\ text {min}} $，而AIC也会增加。简而言之，我们没有发现DE由不同组成部分组成的明显证据。
Dark energy (DE) plays an important role in the expansion history of our universe. But we only got limited knowledge about its nature and properties after decades of study.In most numerical researches, DE is usually considered as a dynamical whole. Actually, multicomponent DE models can also explain the accelerating expansion of our universe, which is accepted theoretically but lack of numerical researches. We try to study the multicomponent DE models from observation by constructing $w_n$CDM models. The total energy density of DE is separated into $n$ ($n=2,3,5$) parts equally and every part has a constant EOS $w_i$ ($i=1,2...n$). We modify the Friedmann equation and the parameterized post-Friedmann description of DE, then put constraints on $w_i$s from Planck 2018 TT,TE,EE$+$lowE$+$lensing, BAO data and PANTHEON samples. The multicomponent DE models are favoured if any $w_n$CDM model is preferred by observational data and there is no overlap between the highest and lowest values of $w_i$s. We find the data combination supports the $w_n$CDM model when $n$ is small and the $w_2$CDM model is slightly preferred by $Δχ^2_{\text{min}} = Δ\text{AIC} =Δ\text{BIC} = -2.48$ over the CPL model, but the largest value of $w_i$ overlaps the smallest one. With larger $n$, the maximum and minimum of $w_i$s do not overlap with each other, but $χ^2_{\text{min}}$ and AIC also increase. In brief, we find no obvious evidence that DE is composed of different components.
