Microwave background radiation as a probe of the contemporary structure and history of the universe
Microwave background radiation as a probe of the contemporary structure and history of the universe
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DOI：
10.1146/annurev.aa.18.090180.002541
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发表时间：
1980-09
影响因子：
33.3
通讯作者：
R. Sunyaev;Y. Zel’dovich
中科院分区：
文献类型：
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作者：
R. Sunyaev;Y. Zel’dovich
假说.微波背景谱的长波部分可以用瑞利定律很好地描述。在短波部分，观察到强度按照黑体光谱减小。辐射在大尺度和小尺度上都是极其各向同性的。没有明显的两极分化。现在人们的兴趣已转移到黑体光谱的偏离上。同样令人感兴趣的是角各向异性，小尺度角波动和偏振的测量。已知的是，这些失真和偏差（光谱和角度两者）是小的。我们相信宇宙可能从来就不是完全均匀的。即使在最早的阶段，物质和辐射密度以及速度场也可能有微小的扰动。火球假说需要这样的扰动来解释星系和星系团的形成。对微波背景辐射的观测是研究这种扰动的一种强有力的方法。即使是由于粘性、导热性和非线性效应而过早消散的扰动，如果还没有影响到宇宙目前的结构，
hypothesis. The longwave part of the microwave background spectrum is quite well described by the Rayleigh-leans law. In the shortwave part the intensity is observed to decrease in accordance with the blackb ody spectrum. The radiation is extremely isotropic on both large and small scales. There is no noticeable polarization. Interest has now shifted to departures of the spectrum from that of a blackbody. Also of great interest are measurements of angular anisotropy, small-scale angular fluctuations, and polarization. What is known already is that these distortions and deviations (both spectral and angular) are small. We believe the universe may never have been completely uniform. Even in the earliest stages there may have been small perturbations of matter and radiation densities, and ofthe velocit y field. The fireball h ypothesis requires such perturbations to account for the formation of galaxies and clusters of galaxies. Observations of the microwave background are a powerful method of investigating such pertu rbations. Even perturbations that are dissipated by viscosity, thermal conductivity, and nonlinear effects too early to influence the present structure of the universe could have dis torted