Infinite Conservation Laws,Continuous Symmetries and Invariant Solutions of Some Discrete Integrable Equations

Two new shift operators are introduced for which a few differential-difference equations are generated by applying the R-matrix method. These equations can be reduced to the standard Toda lattice equation and(1+1)-dimensional and(2+1)-dimensional Toda-type equations which have important applications in hydrodynamics, plasma physics, and so on. Based on these consequences, we deduce the Hamiltonian structures of two discrete systems. Finally,we obtain some new infinite conservation laws of two discrete equations and employ Lie-point transformation group to obtain some continuous symmetries and part of invariant solutions for the(1+1) and(2+1)-dimensional Toda-type equations.