Black hole formation in the early Universe

As supermassive black holes have been observed even at redshift 7, their formation and growth need to be highly efficient in order to obtain final masses of more than 10^9 solar. Theoretical models suggest the formation of their seeds in dark matter halos with virial temperatures above 10^4 K at z~15, as such halos may cool efficiently via atomic hydrogen. At the same time, in order to avoid strong fragmentation, the formation of molecular hydrogen needs to be suppressed, requiring strong radiation backgrounds. In this talk, I will present cosmological hydrodynamics simulations following the collapse in these halos from large cosmological scales down to scales of ~10 AU. The hydrodynamical evolution is followed beyond the formation of the first peak. The simulations demonstrate clearly that occasional fragmentation occurs, but does not prevent the growth of a central massive object. I will stress the role of turbulence and numerical resolution for such studies, and present an outlook for the further evolution.