On a classical limit of q-deformed Whittaker functions
  We provide a derivation of the Givental integral representation of the classical $gl_{\ell+1}$-Whittaker function as a limit $q \to 1$ of the q-deformed $gl_{\ell+1}$-Whittaker function represented as a sum over the Gelfand-Zetlin patterns. 
Anton Gerasimov, Dimitri Lebedev and Sergey Oblezin
math.AG math.RT