The Cosmic Microwave Background Radiation
نویسنده
چکیده
We summarize the theoretical and observational status of the study of the Cosmic Microwave Background radiation. Its thermodynamic spectrum is a robust prediction of the Hot Big Bang cosmology and has been confirmed observationally. There are now 76 observations of Cosmic Microwave Background anisotropy, which we present in a table with references. We discuss the theoretical origins of these anisotropies and explain the standard jargon associated with their observation. 1 Origin of the Cosmic Background Radiation Our present understanding of the beginning of the universe is based upon the remarkably successful theory of the Hot Big Bang. We believe that our universe began about 15 billion years ago as a hot, dense, nearly uniform sea of radiation a minute fraction of its present size (formally an infinitesimal singularity). If inflation occurred in the first fraction of a second, the universe became matter dominated while expanding exponentially and then returned to radiation domination by the reheating caused by the decay of the inflaton. Baryonic matter formed within the first second, and the nucleosynthesis of the lightest elements took only a few minutes as the universe expanded and cooled. The baryons were in the form of plasma until about 300,000 years after the Big Bang, when the universe had cooled to a temperature near 3000 K, sufficiently cool for protons to capture free electrons and form atomic hydrogen; this process is referred to as recombination. The recombination epoch occurred at 1 current address: Center for Astrophysics and Space Sciences, University of California at San Diego, La Jolla, CA 92037
منابع مشابه
Observations of the Cosmic Microwave Background
The properties of the cosmic microwave background radiation provide unique constraints on cosmological models, i.e. on the content, history, and evolution of the Universe. I discuss the latest measurements of the spectral and spatial properties of the cosmic microwave background radiation. Recent measurements from NASA's Cosmic Background Explorer (COBE) satellite, and from balloon-borne and gr...
متن کاملThe Cosmic Microwave Background
I review the discovery of the temperature fluctuations in the cosmic microwave background radiation. The underlying theory and the implications for cosmology are reviewed, and I describe the prospects for future progress.
متن کاملNonparametric Inference for the Cosmic Microwave Background
The Cosmic Microwave Background (CMB), which permeates the entire Universe, is the radiation left over from just 390,000 years after the Big Bang. On very large scales, the CMB radiation field is smooth and isotropic, but the existence of structure in the Universe – stars, galaxies, clusters of galaxies, . . . – suggests that the field should fluctuate on smaller scales. Recent observations, fr...
متن کاملAnisotropic universes with isotropic cosmic microwave background radiation
We show the existence of spatially homogeneous but anisotropic cosmological models whose cosmic microwave background temperature is exactly isotropic at one instant of time but whose rate of expansion is highly anisotropic. The existence of these models shows that the observation of a highly isotropic cosmic microwave background temperature cannot alone be used to infer that the universe is clo...
متن کاملM ay 2 00 0 Big Bang Leftovers in the Microwave : Cosmology with the Cosmic Microwave
Big Bang Leftovers in the Microwave: Cosmology with the Cosmic Microwave Background Radiation
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2000