Fragmentation of the Primordial Gas Clouds and the Lower Limit on the   Mass of the First Stars
  We discuss the fragmentation of primordial gas clouds in the universe after decoupling. Comparing the time scale of collapse with that of fragmentation, we obtain the typical mass of a fragment both numerically and analytically. It is shown that the estimated mass gives the minimum mass of a fragment which is formed from the primordial gas cloud and is essentially determined by the Chandrasekhar mass. 
Hideya Uehara, Hajime Susa, Ryoichi Nishi, Masako Yamada, and Takashi   Nakamura