Darren Reed - February 20, 2015

Numerical simulations for Warm Dark matter and precision cosmology

I discuss results of cosmological simulations in two different
regimes: WDM and precision cosmology.  The numerical challenges of WDM
simulations are similar to those of percent level accurate simulations
for precision cosmology surveys.  Both regimes can be modelled with
gravity-only ("N-body") simulations, but our limited understanding of
galaxy formation makes their interpretation difficult.

I focus on a recent result of WDM simulations:  The cosmic web of
galaxies in a WDM universe, wherein low mass halo formation is heavily
suppressed, is nearly indistinguishable to that of a CDM universe
whose low mass are dark.  It is thus difficult to confirm whether the
solution to the "missing satellite problem" is astrophysical or a
cosmological.  However, future deep surveys of the local universe able
to sample faint galaxies in small voids have the potential to
constrain simultaneously the "warmth" (i.e. the mass) of the dark
matter particle and the physics of galaxy formation in low mass halos.