Cosmic neutrino background

A neutrino lighter than 1 MeV decouples while relativistic. If it is so light to be still relativistic today (rnv 0.1 meV), its relic density is pp = 77t27 / I20. If it became non-relativistic after decoupling, its relic density is determined by its equilibrium number density as pv = mI,3C(3)T,3/27r2. Here Tv = (3/ll)1//3T7, where T7 = 2.725 0.002K is the cosmic microwave background temperature. (We use natural units, c- h, I.)... 

We should acknowledge that there are two basic possibilities of variations of constants. One is a result of certain violation of LPl, while the other is an observational effect of the interaction with environment, such as the bath of Cosmic Microwave Background (CMB) radiation of photons, neutrinos, gravitons. Dark Matter (DM), matter, etc. 

The neutrino analogue of the cosmic "microwave background radiation, i.e. a background radiation consisting of neutrinos. The CNB has not yet been detected it is thought that it would have a temperature of about 1.9 kelvin. 

The neutrino Sun never sets. Sixty billion neutrinos blasted out from the Sun s core eight minutes ago fly through every square centimetre of our body each second. We feel absolutely nothing and neither do they. They are the height of discretion. The night is not absolutely dark because, not only are we forever bathed in the cosmic background radiation at microwave wavelengths, but we... 

Fiber optic data cable will stretch from the shore for 30 km to a connector box some 4800 meters below the ocean surface. Strings of nine separate cables will rise vertically about 280 meters above the ocean floor. Each cable, held up by a float, will contain 24 detectors. The apparatus, referred to as a neutrino telescope, will have to pick up at least ten muon events per year from any given 1° patch of sky for the DUMAND scientists to be confident that they have a significant neutrino source, not just a few background pulses from non-ncutrino cosmic rays,... 

Microwave background. The very high temperature of the Big Bang is still visible in the microwave background, a universal radiation field of 2.73 K. There is a corresponding cosmic bath of low-energy neutrinos. Both... 

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