WIMP DM and first stars: suppression of fragmentation in primordial star
  formation
  We present the first 3D simulations to include the effects of dark matter
annihilation feedback during the collapse of primordial mini-halos. We begin
our simulations from cosmological initial conditions and account for dark
matter annihilation in our treatment of the chemical and thermal evolution of
the gas. The dark matter is modelled using an analytical density profile that
responds to changes in the peak gas density. We find that the gas can collapse
to high densities despite the additional energy input from the dark matter. No
objects supported purely by dark matter annihilation heating are formed in our
simulations. However, we find that the dark matter annihilation heating has a
large effect on the evolution of the gas following the formation of the first
protostar. Previous simulations without dark matter annihilation found that
protostellar discs around Population III stars rapidly fragmented, forming
multiple protostars that underwent mergers or ejections. When dark matter
annihilation is included, however, these discs become stable to radii of 1000
AU or more. In the cases where fragmentation does occur, it is a wide binary
that is formed.
