Dark Stars: Improved Models and First Pulsation Results
  We use the stellar evolution code MESA to study dark stars. Dark stars (DSs),
which are powered by dark matter (DM) self-annihilation rather than by nuclear
fusion, may be the first stars to form in the Universe. We compute stellar
models for accreting DSs with masses up to 10^6 M_{sun}. The heating due to DM
annihilation is self-consistently included, assuming extended adiabatic
contraction of DM within the minihalos in which DSs form. We find remarkably
good overall agreement with previous models, which assumed polytropic
interiors. There are some differences in the details, with positive
implications for observability. We found that, in the mass range of 10^4 -10^5
M_{sun}, our DSs are hotter by a factor of 1.5 than those in Freese et
al.(2010), are smaller in radius by a factor of 0.6, denser by a factor of 3 -
4, and more luminous by a factor of 2. Our models also confirm previous
results, according to which supermassive DSs are very well approximated by
(n=3)-polytropes. We also perform a first study of dark star pulsations. Our DS
models have pulsation modes with timescales ranging from less than a day to
more than two years in their rest frames, at z ~ 15, depending on DM particle
mass and overtone number. Such pulsations may someday be used to identify
bright, cool objects uniquely as DSs; if properly calibrated, they might, in
principle, also supply novel standard candles for cosmological studies.
