Approximate symmetries and conservation laws with applications (Q1964578)

The authors deal with the theory of approximate symmetries associated with differential equations with a small parameter. They show that approximate conservation laws can be associated with approximate Lie-Bäcklund symmetries for systems which may not possess a Lagrangian. In addition, the authors prove that these conservation laws may be constructed algorithmically which allows them to apply the results to certain classes of linear and nonlinear wave equations.