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Cosmic microwave background spectral distortions – Fluctuations in the energy spectrum of the microwave background Cosmological perturbation theory – theory by which the evolution of structure is understood in the big bang model Pages displaying wikidata descriptions as a fallback
1938: Walther Nernst re-estimates the cosmic ray temperature as 0.75 K. [2] 1946: The term "microwave" is first used in print in an astronomical context in an article "Microwave Radiation from the Sun and Moon" by Robert Dicke and Robert Beringer. 1946: Robert Dicke predicts a microwave background radiation temperature of 20 K (ref: Helge Kragh)
The discovery of cosmic microwave background radiation constitutes a major development in modern physical cosmology. In 1964, US physicist Arno Allan Penzias and radio-astronomer Robert Woodrow Wilson discovered the cosmic microwave background (CMB) , estimating its temperature as 3.5 K, as they experimented with the Holmdel Horn Antenna .
Differences in the temperature of the cosmic background are smoothed by cosmic inflation, but they still exist. The theory predicts a spectrum for the anisotropies in the microwave background which is mostly consistent with observations from WMAP and COBE. [6] However, gravity alone may be sufficient to explain this homogeneity. [7]
CMB spectral distortions are tiny departures of the average cosmic microwave background (CMB) frequency spectrum from the predictions given by a perfect black body.They can be produced by a number of standard and non-standard processes occurring at the early stages of cosmic history, and therefore allow us to probe the standard picture of cosmology.
RELIKT-1, a Soviet cosmic microwave background anisotropy experiment on board the Prognoz 9 satellite (launched 1 July 1983), gave the first upper limits on the large-scale anisotropy. [33]: 8.5.3.2 The other key event in the 1980s was the proposal by Alan Guth for cosmic inflation. This theory of rapid spatial expansion gave an explanation for ...
The Sunyaev–Zeldovich effect (named after Rashid Sunyaev and Yakov B. Zeldovich and often abbreviated as the SZ effect) is the spectral distortion of the cosmic microwave background (CMB) through inverse Compton scattering by high-energy electrons in galaxy clusters, in which the low-energy CMB photons receive an average energy boost during collision with the high-energy cluster electrons.
The limit is set by the slowing effect of interactions of the protons with the microwave background radiation over long distances (≈ 160 million light-years). The limit is at the same order of magnitude as the upper limit for energy at which cosmic rays have experimentally been detected, although indeed some detections appear to have exceeded ...