LIE SYMMETRIES OF TWO (2+1)-DIMENSIONAL TODA-LIKE LATTICES BY THE EXTENDED DIFFERENTIAL FORM METHOD

摘要

Based on the extended Harrison and Estabrook's differential form method, we obtain the Lie symmetries of two (2+1)-dimensional Toda-like lattices from two different sets of differential forms, respectively. Moreover it is shown that, for each lattice, the determining equations for the two sets give the same symmetries; and the set of differential forms for the lower-dimensional space can make the computation for finding symmetries simpler than the other.