Astroparticle Physics
Thermalisation of light sterile neutrinos
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Europe/Berlin
Building 67, SemRm 10 (DESY Hamburg)
Building 67, SemRm 10
DESY Hamburg
Description
Abstract:
Sterile neutrinos in the eV mass range are often invoked to explain terestrial neutrino experiments. Given the preferred mass and mixing angle, such a sterile neutrino will thermalise completely in the early universe and are at odds with observations of the large scale structure.
A partially thermalised sterile neutrino is still allowed however, and such a neutrino can also alleviate some of the tension found in current datasets such as BICEP2 and Planck.
I will explain the current cosmological constraints on sterile neutrinos and then discuss two different ways of inhibiting sterile neutrino production: A large lepton asymmetry in the active neutrino sector, or a new hidden gauge boson in the sterile neutrino sector.
Sterile neutrinos in the eV mass range are often invoked to explain terestrial neutrino experiments. Given the preferred mass and mixing angle, such a sterile neutrino will thermalise completely in the early universe and are at odds with observations of the large scale structure.
A partially thermalised sterile neutrino is still allowed however, and such a neutrino can also alleviate some of the tension found in current datasets such as BICEP2 and Planck.
I will explain the current cosmological constraints on sterile neutrinos and then discuss two different ways of inhibiting sterile neutrino production: A large lepton asymmetry in the active neutrino sector, or a new hidden gauge boson in the sterile neutrino sector.