  We use loop group techniques to construct a quantum field theory model of
anyons on a circle and at finite temperature. We find an anyon Hamiltonian
providing a second quantization of the elliptic Calogero-Sutherland model. This
allows us to prove a remarkable identity which is a starting point for an
algorithm to construct eigenfunctions and eigenvalues of the elliptic
Calogero-Sutherland Hamiltonian (this algorithm is elaborated elsewhere).
  This paper contains a detailed introduction, technical details and proofs.
