Ve. Adler et It. Habibullin, INTEGRABLE BOUNDARY-CONDITIONS FOR THE TODA LATTICE, Journal of physics. A, mathematical and general, 28(23), 1995, pp. 6717-6729
The problem of construction of the boundary conditions for the Toda la
ttice compatible with its higher symmetries is considered. It is demon
strated that this problem is reduced to finding the differential const
raints consistent with the ZS-AKNS hierarchy. A method of their constr
uction is offered based on the Backlund transformations. It is shown t
hat the generalized Toda lattices corresponding to the non-exceptional
Lie algebras of finite growth can be obtained by imposing one of the
four simplest integrable boundary conditions on both ends of the latti
ce. This fact allows, in particular, the solution of the reduction pro
blem of the series A Toda lattices into the series D lattices. Deforma
tions of the found boundary conditions are presented which lead to the
Painleve-type equations.