Correlation energy in a spin polarized two dimensional electron liquid   in the high density limit
  We have obtained an analytic expression for the ring diagrams contribution to the correlation energy of a two dimensional electron liquid as a function of the uniform fractional spin polarization. Our results can be used to improve on the interpolation formulas which represent the basic ingredient for the constructions of modern spin-density functionals in two dimensions. 
S. Chesi and G. F. Giuliani