Relativistic effective degrees of freedom and quantum statistics of neutrinos

Abstract

Analytical expressions of the relativistic effective degrees of freedom [Formula: see text] with non-pure fermionic neutrinos are presented. A semi-analytical study is performed to show that [Formula: see text] with pure fermionic neutrinos may be greater than [Formula: see text] with pure bosonic neutrinos for nonvanishing lepton flavor asymmetries.