Noether symmetries of dynamics for non-conservative systems with time delay

Abstract

The Noether symmetries and the conserved quantities of dynamics for non-conservative systems with time delay are proposed and studied. Firstly, the Hamilton principle for non-conservative systems with time delay is established, and the Lagrange equations with time delay are obtained. Secondly, based upon the invariance of the Hamilton action with time delay under a group of infinitesimal transformations which depends on the generalized velocities, the generalized coordinates and the time, the Noether symmetric transformations and the Noether quasi-symmetric transformations of the system are defined and the criteria of the Noether symmetries are established. Finally, the relationship between the symmetries and the conserved quantities are studied, and the Noether theory of non-conservative systems with time delay is established At the end of the paper, some examples are given to illustrate the application of the results.