On the Small-Scale Clustering of Ly-alpha Forest Clouds
  Recent measurements of the autocorrelation function of the Ly-alpha clouds are analyzed from the point of view of a simple model with strong clustering on the small scales. It is shown that this toy model reproduces fairly well the important linear relation between amplitude of the absorber autocorrelation function and neutral hydrogen column density. In addition, it predicts a correct evolutionary trend of correlation amplitudes. Some possible ramifications of these results are discussed. 
Milan M. Cirkovic and Kenneth M. Lanzetta