Speaker
Mr
Maximilian Totzauer
(Max-Planck-Institute for Physics)
Description
Sterile neutrinos in the keV range are among the most promising
candidates for dark matter. We investigate in detail a model that
extends the Standard Model by a scalar singlet S and sterile
neutrinos N_i.
The scalar couples to the Standard Model via a Higgs portal
coupling, the size of which determines whether or not the scalar
singlet S enters thermal equilibrium in the early Universe. Sterile
neutrinos N_i on the other hand couple to the scalar via a Yukawatype
interaction and also mix with active neutrino sector in
general.
We present both analytical and numerical methods to solve the
corresponding Boltzmann equations on the level of distribution
functions, from which all relevant information can be extracted. We
explore the paramter space of this setting by imposing limits from
cosmological observations like the relic abundance, the effective
number of neutrinos, or considerations of structure formation.
Exploiting the distribution functions obtained, we show that some
previous estimates on structure formation present in the literature
can be refined considerably, opening up possibilities to address
recent issues on structure formation on small scales. By comparing
numerical computations to analytical estimates already present in
the literature, we gain a deeper insight on the validity of some
assumptions that have been made so far.
Primary author
Mr
Maximilian Totzauer
(Max-Planck-Institute for Physics)
