Deutsches Elektronen-Synchrotron DESY, Theory Group, D-22603 Hamburg, Germany.
Université de Genève, Département de Physique Théorique and CAP, 24 quai Ernest-Ansermet, CH-1211 Genève 4, Switzerland.
Phys Rev Lett. 2014 Jun 6;112(22):221301. doi: 10.1103/PhysRevLett.112.221301.
Local measurements of the Hubble expansion rate are affected by structures like galaxy clusters or voids. Here we present a fully relativistic treatment of this effect, studying how clustering modifies the mean distance- (modulus-)redshift relation and its dispersion in a standard cold dark matter universe with a cosmological constant. The best estimates of the local expansion rate stem from supernova observations at small redshifts (0.01<z<0.1). It is interesting to compare these local measurements with global fits to data from cosmic microwave background anisotropies. In particular, we argue that cosmic variance (i.e., the effects of the local structure) is of the same order of magnitude as the current observational errors and must be taken into account in local measurements of the Hubble expansion rate.
局部哈勃膨胀率的测量会受到星系团或空洞等结构的影响。在这里，我们提出了一种完全相对论的处理方法，研究了聚类如何在一个具有宇宙常数的标准冷暗物质宇宙中修改平均距离-（模）红移关系及其分散度。局部膨胀率的最佳估计值来自于小红移（0.01<z<0.1）处的超新星观测。将这些局部测量值与对宇宙微波背景各向异性数据的全局拟合进行比较是很有趣的。特别是，我们认为宇宙方差（即局部结构的影响）与当前观测误差具有相同的量级，在局部哈勃膨胀率的测量中必须考虑到这一点。
