Subsymmetries and Their Properties

Abstract

We introduce a subsymmetry of a differential system as an infinitesimal transformation of a subset of the system that leaves the subset invariant on the solution set of the entire system. We discuss the geometric meaning and properties of subsymmetries and also an algorithm for finding subsymmetries of a system. We show that a subsymmetry is a significantly more powerful tool than a regular symmetry with regard to deformation of conservation laws. We demonstrate that all lower conservation laws of the nonlinear telegraph system can be generated by system subsymmetries.