Lindhard function of a d-dimensional Fermi gas
  We review in detail the derivation of the dielectric response function of a noninteracting system of spin-1/2 fermions in the random-phase approximation. Results for the response function of a Fermi gas in one, two and three dimensions can be obtained in closed form, and represent the baseline for developing a pedagogical understanding of the effect of correlations on the response functions in interacting systems of fermions. 
Bogdan Mihaila
cond-mat.quant-gas cond-mat.str-el math-ph math.MP