标题： 缓解宇宙学张力的混合暗物质扇区 显示英文标题

标题： Alleviating cosmological tensions with a hybrid dark sector

摘要： 我们研究了一种受混合暴胀启发的宇宙学模型，其中两个标量场分别代表暗能量（DE）和暗物质（DM），并通过一种与DE标量场$1/\phi$成正比的耦合相互作用。耦合强度完全由标量场$\phi_i$的初始条件决定，该参数化描述了偏离标准$\Lambda$CDM模型的情况。在这个模型中，标量场在物质主导时期跟踪暗物质的行为，直到过渡到暗能量，而在此期间暗物质成分的衰变速率比标准CDM更快，因此不同于一些类似幻影暗能量的相互作用暗物质-暗能量模型。利用\textit{普朗克}2018年的CMB数据、DESI BAO测量以及Pantheon+超新星观测，我们发现该模型允许$H_0$增加，这有助于缓解哈勃张力。 此外，我们发现耦合参数的较高值与较低的$\omega_m$值相关联，并且弱引力透镜参数$S_8$有轻微下降，这可能有助于解决$S_8$紧张问题。 然而，贝叶斯模型比较对于大多数数据集显示出了不确定的结果，除非包含 S$H_0$ES 数据，在这种情况下，发现适度的证据支持混合模型。 显示英文摘要

摘要： We investigate a cosmological model inspired by hybrid inflation, where two scalar fields representing dark energy (DE) and dark matter (DM) interact through a coupling that is proportional to the DE scalar field $1/\phi$. The strength of the coupling is governed solely by the initial condition of the scalar field, $\phi_i$, which parametrises deviations from the standard $\Lambda$CDM model. In this model, the scalar field tracks the behaviour of DM during matter-domination until it transitions to DE while the DM component decays quicker than standard CDM during matter-domination, and is therefore different from some interacting DM-DE models which behaves like phantom dark energy. Using \textit{Planck} 2018 CMB data, DESI BAO measurements and Pantheon+ supernova observations, we find that the model allows for an increase in $H_0$ that can help reduce the Hubble tension. In addition, we find that higher values of the coupling parameter are correlated with lower values of $\omega_m$, and a mild decrease of the weak-lensing parameter $S_8$, potentially relevant to address the $S_8$ tension. Bayesian model comparison, however, reveals inconclusive results for most datasets, unless S$H_0$ES data are included, in which case a moderate evidence in favour of the hybrid model is found.