We introduce a new integrable hierarchy of nonlinear differential-difference equations which is subhierarchy the 2D Toda lattice defined by imposing constraint to Lax operators latter. The with can be regarded as discretization BKP hierarchy. construct its algebraic-geometrical solutions in terms Riemann and Prym theta-functions.

Given a finite, flat morphism between embeddable noetherian schemes of pure dimension 1, we define the notion direct and inverse image for generalized divisors line bundles. In case when deal with (possibly reducible, non-reduced) projective curves over field codomain curve is smooth, introduce compactified Jacobians parametrizing torsion-free rank-1 sheaves study Norm maps Jacobians. Finally, ...