Varying Constants, Gravitation and Cosmology.
Varying Constants, Gravitation and Cosmology.
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不同常数，引力和宇宙学。
DOI：
10.12942/lrr-2011-2
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发表时间：
2011
影响因子：
40.6
通讯作者：
Uzan JP
中科院分区：
文献类型：
--
作者：
Uzan JP
基本常数是我们物理定律的基石。任何在空间和/或时间上变化的常数都会反映出与物质耦合的几乎没有质量的场的存在。这将导致违反自由落体的普遍性。因此，对于我们理解引力和广义相对论的有效性领域来说，检验它们的恒常性是极其重要的。详细讨论了这些常数之间的关系，以及自由落体的局部位置不变性和普适性的检验。然后，我们回顾了从原子钟、奥克洛现象、太阳系观测、陨石定年、类星体吸收光谱、恒星物理、脉冲星计时、宇宙微波背景和大爆炸核合成中获得的主要实验和观测约束。在每个步骤中，我们描述了每个系统的基础，它与常数的依赖关系，已知的系统效应和最近得到的约束。然后，我们描述了低能常数实际上可能变化的主要理论框架，并重点讨论了统一机制和不同常数变化之间的关系。最后，我们将讨论理解它们的数值和它们所面临的明显微调的可能性。
Fundamental constants are a cornerstone of our physical laws. Any constant varying in space and/or time would reflect the existence of an almost massless field that couples to matter. This will induce a violation of the universality of free fall. Thus, it is of utmost importance for our understanding of gravity and of the domain of validity of general relativity to test for their constancy. We detail the relations between the constants, the tests of the local position invariance and of the universality of free fall. We then review the main experimental and observational constraints that have been obtained from atomic clocks, the Oklo phenomenon, solar system observations, meteorite dating, quasar absorption spectra, stellar physics, pulsar timing, the cosmic microwave background and big bang nucleosynthesis. At each step we describe the basics of each system, its dependence with respect to the constants, the known systematic effects and the most recent constraints that have been obtained. We then describe the main theoretical frameworks in which the low-energy constants may actually be varying and we focus on the unification mechanisms and the relations between the variation of different constants. To finish, we discuss the more speculative possibility of understanding their numerical values and the apparent fine-tuning that they confront us with.