It is thought that there are approximately 10^80 protons in the observable universe, but there are approximately 10^90 photons in the observable universe. If my googling is correct, there are also approximately 10^90 neutrinos in the observable universe, but their temperature is only 1.9 degrees Kelvin, compared to 2.7 degrees Kelvin for the photons. How many gravitons are there in the observable universe? (And what is their temperature?) Is this number also approximately equal to 10^90? Why or why not? The photons and neutrinos are supposedly relics of the big bang. But we have just (Bicep 2) (indirectly) detected gravitons which are relics of inflation. Does this make a difference? Are there photons and neutrinos which are relics of inflation also?