标题： LTB空腔宇宙中的红移漂移 显示英文标题

标题： Redshift Drift in LTB Void Universes

摘要： 我们研究了红移漂移，即宇宙红移随时间的变化率，在Lemaître-Tolman-Bondi（LTB）解中观测者位于对称中心的情况。这种解常被作为反哥白尼宇宙模型来解释宇宙体积膨胀加速，而无需引入暗能量的概念。LTB宇宙模型与包含暗能量的哥白尼宇宙模型之间被认为有一个决定性的差异就是红移漂移。所有已知的LTB宇宙模型中的红移漂移都为负值，而在包含暗能量的哥白尼模型中，红移漂移在红移域$z \lesssim 2$内为正值。然而，关于这一主题尚未有过详细的研究。在本文中，我们证明了对于LTB空洞模型，离心源的红移漂移总是负值。我们也表明，当存在极大的山峰型非均匀性时，红移漂移可以为正。我们的结果表明，通过观察红移漂移，我们可以确定我们是否生活在没有暗能量的大空洞的中心附近。 显示英文摘要

摘要： We study the redshift drift, i.e., the time derivative of the cosmological redshift in the Lema\^itre-Tolman-Bondi (LTB) solution in which the observer is assumed to be located at the symmetry center. This solution has often been studied as an anti-Copernican universe model to explain the acceleration of cosmic volume expansion without introducing the concept of dark energy. One of decisive differences between LTB universe models and Copernican universe models with dark energy is believed to be the redshift drift. The redshift drift is negative in all known LTB universe models, whereas it is positive in the redshift domain $z \lesssim 2$ in Copernican models with dark energy. However, there have been no detailed studies on this subject. In the present paper, we prove that the redshift drift of an off-center source is always negative in the case of LTB void models. We also show that the redshift drift can be positive with an extremely large hump-type inhomogeneity. Our results suggest that we can determine whether we live near the center of a large void without dark energy by observing the redshift drift.