Physics – Nuclear Physics
Scientific paper
Oct 2000
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2000aps..dnp.jb012m&link_type=abstract
American Physical Society, Division of Nuclear Physics Meeting, October 4-7, 2000 Williamsburg, VA, abstract #JB.012
Physics
Nuclear Physics
Scientific paper
We reanalyze cosmological constraints on a net universal lepton asymmetry. For sufficiently large neutrino degeneracy, weak decoupling can occur before the QCD phase transition. The decoupled neutrinos then have a much lower relic temperature due to the large change in particle degees of freedom which subsequently heat photons by entropy consideration. This changes the expansion rate during the subsequent nucleosynthesis, photon decoupling and galaxy formation epochs. In particular, we show that the nucleosynthesis constraints are satisfied by a new one parameter family of solutions for the baryon to photon ratio and degeneracies for the three neutrino types. Values of the baryon density sufficient to close the universe are even allowed. At the same time new microwave background measurements seem to require a larger baryon density which is easily accomodated by these neutrino degenerate models. We show that model solutions exist which circumvent previously adopted limits to neutrino degeneracy. Optimum cosmological models based upon all available constraints are identified.
Boyd Richard
Kajino Toshitaka
Mathews Grant
Orito Manabu
No associations
LandOfFree
New Limits on Neutrino Degeneracy from Primordial Nucleosynthesis does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with New Limits on Neutrino Degeneracy from Primordial Nucleosynthesis, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and New Limits on Neutrino Degeneracy from Primordial Nucleosynthesis will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1769401