2
votes
1answer
41 views

Experimental evidence for the relic neutrinos

What are the experimental (indirect) evidence for the cosmic neutrino background? Where can I read more about this? The discussion on the wikipedia page about the C$\nu$B seems to me to be more ...
1
vote
3answers
399 views

black body and cosmic microwave background radiation

Why is the sprectum of the cosmic microwave background radiation (or seems to be) that of a black body?
3
votes
2answers
103 views

Cosmic radiation cutoff at LOW energies?

The energy spectrum of the cosmic radiation (not CMB) is limited to both sides. I know about the GZK-cutoff at high energies. Basically the interaction probability for photons of energies above 10^20 ...