Spin polarization and effective mass: a numerical study in disordered   two dimensional systems
  We numerically study the magnetization of small metallic clusters. The magnetic susceptibility is enhanced for lower electronic densities due to the stronger influence of electron-electron interactions. The magnetic susceptibility enhancement stems mainly from an enhancement of the mass for commensurate fillings, while for non-commensurate fillings its a result of an enhancement of the Land\'e $g$ factor. The relevance to recent experimental measurements is discussed. 
Richard Berkovits