哈勃常数购买指南
A buyer's guide to the Hubble Constant
摘要：
自从埃德温·哈勃和乔治·勒梅特在大约一个世纪前首次提出宇宙膨胀以来，测量宇宙膨胀率的哈勃常数H0就引起了天文学家的极大兴趣。除了它本身很有趣之外，没有它就无法推导出宇宙的一些性质。在过去的十年里，不同的测量方法之间出现了巨大的差距，一些方法定位在附近的宇宙中，另一些则定位在宇宙学距离上。SH0ES团队在局部发现了$H_0 = 73.2 \pm 1.3$ km sec $^{-1}$ Mpc $^{-1}$，而普朗克合作组织通过测量宇宙微波背景发现的早期宇宙的数值是$H_0 = 67.4 \pm 0.5$ km sec $^{-1}$ Mpc $^{-1}$。这个缺口是不是意味着已经建立的$Λ$ CDM宇宙学模型是不完整的？还是有未知的系统？更实际的是，如果需要为某个目的假设一个值，谦逊的天文学家应该如何在相互竞争的说法中做出选择？在这篇文章中，我们将回顾这些结果，以及需要对宇宙学模型进行什么样的改变才能适应它们。对于赶时间的天文学家，我们提供了购买者的结果指南，并提出建议。
英文摘要：
Since the expansion of the universe was first established by Edwin Hubble and Georges Lemaitre about a century ago, the Hubble constant H0 which measures its rate has been of great interest to astronomers. Besides being interesting in its own right, few properties of the universe can be deduced without it. In the last decade a significant gap has emerged between different methods of measuring it, some anchored in the nearby universe, others at cosmological distances. The SH0ES team has found $H_0 = 73.2 \pm 1.3$ km sec$^{-1}$ Mpc$^{-1}$ locally, whereas the value found for the early universe by the Planck Collaboration is $H_0 = 67.4 \pm 0.5$ km sec$^{-1}$ Mpc$^{-1}$ from measurements of the cosmic microwave background. Is this gap a sign that the well-established $Λ$CDM cosmological model is somehow incomplete? Or are there unknown systematics? And more practically, how should humble astronomers pick between competing claims if they need to assume a value for a certain purpose? In this article, we review results and what changes to the cosmological model could be needed to accommodate them all. For astronomers in a hurry, we provide a buyer's guide to the results, and make recommendations.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
