Dark matter annihilation might power the first luminous stars in the
Universe. This type of stars, known as Dark Stars, could form in 10^6-10^8
solar mass protohalos at redshifts z around 20, and they could be much more
luminous and larger in size than ordinary stars powered by nuclear fusion. We
investigate the formation of Dark Stars in the self-interacting dark matter
(SIDM) scenario. We present a concrete particle physics model of SIDM that can
simultaneously give rise to the observed dark matter density, satisfy
constraints from astrophysical and terrestrial searches, and address the
various small-scale problems of collisionless dark matter via the
self-interactions. In this model, the power from dark matter annihilation is
deposited in the baryonic gas in environments where Dark Stars could form. We
further study the evolution of SIDM density profiles in the protohalos at z
around 20. As the baryon cloud collapses due to the various cooling processes,
the deepening gravitational potential can speed up gravothermal evolution of
the SIDM halo, yielding sufficiently high dark matter densities for Dark Stars
to form. We find that SIDM-powered Dark Stars can have similar properties, such
as their luminosity and size, as Dark Stars predicted in collisionless dark
matter models.Comment: 11 pages, 4 figure