Supersonic turbulence fragments the interstellar medium into dense sheets , filaments , cores and large low density voids , thanks to a complex network of highly radiative shocks .
The turbulence is driven on large scales , predominantly by supernovae .
While on scales of the order of the disk thickness the magnetic energy is in approximate equipartition with the kinetic energy of the turbulence , on scales of a few pc the turbulent kinetic energy significantly exceeds the magnetic energy .

The scaling properties of supersonic turbulence are well described by a new analytical theory , which allows to predict the structure functions of the density and velocity distributions in star-forming clouds up to very high order .

The distribution of core masses depends primarily on the power spectrum of the turbulent flow , and on the jump conditions for isothermal shocks in a magnetized gas .
For the predicted velocity power spectrum index \beta = 1.74 , consistent with results of numerical experiments of supersonic turbulence as well as with Larson ’ s velocity-size relation , one obtains by scaling arguments a power law mass distribution of dense cores with a slope equal to 3 / ( 4 - \beta ) = 1.33 , consistent with the slope of the Salpeter stellar initial mass function ( IMF ) .
Results from numerical simulations confirm this scaling .
Both the analytical model for the stellar IMF and its numerical estimate show that turbulent fragmentation can also explain the origin of brown dwarfs .
The analytical predictions for the relative abundance of brown dwarfs are confirmed by the observations .

The main conclusion is that the stellar IMF directly reflects the mass distribution of prestellar cores , due predominantly to the process of turbulent fragmentation .