Temperature distribution of neutrino background radiation

[Amir Livne]

Hello.

I wonder - is the CνB energy curve expected to follow the Boltzmann distribution?
In the 2 seconds neutrinos were in equilibrium with matter, did they bounce off enough to even out the energy?

I'm asking because a back-of-envelope computation gives cosmic neutrino speeds of ~0.09c, whereas neutrinos from solar events, geoneutrinos, supernovas etc. travel so close to c we can't distinguish them.

So is there a clear distinction, CνB radiation is slow, and modern neutrinos are fast?

 

[robert2734]

Don't you need to know the rest mass of the neutrino to solve for its velocity?

 

[mathman]

Hello.

I wonder - is the CνB energy curve expected to follow the Boltzmann distribution?
In the 2 seconds neutrinos were in equilibrium with matter, did they bounce off enough to even out the energy?

I'm asking because a back-of-envelope computation gives cosmic neutrino speeds of ~0.09c, whereas neutrinos from solar events, geoneutrinos, supernovas etc. travel so close to c we can't distinguish them.

So is there a clear distinction, CνB radiation is slow, and modern neutrinos are fast?

You're probably right. Today neutrinos can go a long time without interacting with anything.