  Cosmological hydrodynamical simulations of primordial star formation suggest
that the gas within the first star-forming halos is turbulent. This has strong
implications on the subsequent evolution, in particular on the generation of
magnetic fields. Using high-resolution numerical simulations, we show that in
the presence of turbulence, weak seed magnetic fields are exponentially
amplified by the small-scale dynamo during the formation of the first stars. We
conclude that strong magnetic fields are generated during the birth of the
first stars in the universe, potentially modifying the mass distribution of
these stars and influencing the subsequent cosmic evolution. We find that the
presence of the small-scale turbulent dynamo can only be identified in
numerical simulations in which the turbulent motions in the central core are
resolved with at least 32 grid cells.

Cosmology and Nongalactic Astrophysics