Lie point symmetries of differential--difference equations

D. Levi, P. Winternitz, R. Yamilov

Published 2010-04-29Version 1

We present an algorithm for determining the Lie point symmetries of differential equations on fixed non transforming lattices, i.e. equations involving both continuous and discrete independent variables. The symmetries of a specific integrable discretization of the Krichever-Novikov equation, the Toda lattice and Toda field theory are presented as examples of the general method.