标题： DESI 之后的物理与幻影暗能量：在弯曲的背景中融化精髓 显示英文标题

标题： Physical vs phantom dark energy after DESI: thawing quintessence in a curved background

摘要： 近期来自DESI的数据，结合其他数据，提供了关于动力学暗能量的中等证据，$w\neq-1$。在$w_0, w_a$参数化$w$中，存在对于红移为$z\sim0.5$时的幻影穿越，$w<-1$的偏好。在广义相对论中，幻影状态方程是不物理的。因此，检查在其他物理自洽的暗能量模型中是否存在幻影穿越非常重要，这些模型与$w_0, w_a$参数化的证据相当。我们发现，在非零宇宙曲率的退冻拟正物质背景下，基于参数化和现实标量场演化，它可以很好地拟合近期数据，与在平坦背景下的$w_0, w_a$相当。 尽管现实模型不允许$w<-1$，但参数化允许它。 然而，即使我们允许$w<-1$，数据也不支持幻影穿越。 因此，幻影穿越是基于非物理模型的参数化的一种人为结果。 显示英文摘要

摘要： Recent data from DESI, in combination with other data, provide moderate evidence of dynamical dark energy, $w\neq-1$. In the $w_0, w_a$ parametrization of $w$, there is a preference for a phantom crossing, $w<-1$, at redshift $z\sim0.5$. In general relativity, the phantom equation of state is unphysical. Thus it is important to check whether phantom crossing is present in other physically self-consistent models of dark energy that have equivalent evidence to the $w_0, w_a$ parametrization. We find that thawing quintessence with nonzero cosmic curvature can fit the recent data as well as $w_0, w_a$ in a flat background, based on both parametric and realistic scalar field evolutions. Although the realistic model does not allow $w<-1$, the parametrizations do allow it. However even if we allow $w<-1$ the data do not enforce phantom crossing. Thus, the phantom crossing is an artifact of a parametrization that is not based on a physical model.