Gelfand and Kolmogorov numbers of Sobolev embeddings of weighted   function spaces
  In this paper we study the Gelfand and Kolmogorov numbers of Sobolev embeddings between weighted function spaces of Besov and Triebel-Lizorkin type with polynomial weights. The sharp asymptotic estimates are determined in the so-called non-limiting case. 
Shun Zhang, Gensun Fang
math.FA math.NA