Finite-gap difference opeators with elliptic coefficients and their spectral curves

Abstract

We review recent results on the finite-gap properties of difference operators with elliptic coefficients and give explicit characterization of spectral curves for difference analogues of the higher Lam\'e operators. This curve parametrizes double-Bloch solutions to the difference Lam\'e equation. The curve depends on a positive integer number \ell, related to its genus g by g=2\ell, and two continuous parameters: the lattice spacing \eta and the modular parameter \tau. Isospectral deformations of the difference Lam\'e operator under Volterra flows are also discussed.