title: Coherent active-sterile neutrino flavor transformation in the early universe.
abstract: We solve the problem of coherent Mikheyev-Smirnov-Wolfenstein resonant active-to-sterile neutrino flavor conversion driven by an initial lepton number in the early Universe. We find incomplete destruction of the lepton number in this process and a sterile neutrino energy distribution with a distinctive cusp and high energy tail. These features imply alteration of the nonzero lepton number primordial nucleosynthesis paradigm when there exist sterile neutrinos with rest masses m(s) approximately 1 eV. This could result in better light element probes of (constraints on) these particles.
authors.affiliation: Department of Physics, University of California-San Diego, La Jolla, California 92093-0319, USA. ckishimo@ucsd.edu
authors.forename: Chad T
authors.initials: CT
authors.lastname: Kishimoto
authors.forename: George M
authors.initials: GM
authors.lastname: Fuller
authors.forename: Christel J
authors.initials: CJ
authors.lastname: Smith