| Abstract: | Differential-difference equations of the form u? n = F n (t, un?1, u n , un+1, u?n?1, u? n , u?n+1) are classified according to their intrinsic Lie point symmetries, equivalence group and some low-dimensional Lie algebras including the Abelian symmetry algebras, nilpotent nonAbelian symmetry algebras, solvable symmetry algebras with nonAbelian nilradicals, solvable symmetry algebras with Abelian nilradicals and nonsolvable symmetry algebras. Here F n is a nonlinear function of its arguments and the dot over u denotes differentiation with respect to t. |
