Perturbation to Noether symmetries and adiabatic invariants for disturbed Hamiltonian systems based on El-Nabulsi nonconservative dynamics model

This paper focuses on studying the perturbation to the Noether symmetries and the adiabatic invariants for nonconservative dynamic systems in phase space under nonconservative dynamics model presented by El-Nabulsi. First of all, the El-Nabulsi dynamics model for a nonconservative system is introduced and the El-Nabulsi–Hamilton canonical equations are established. Secondly, the basic formulae for the variation of El-Nabulsi–Hamilton action in phase space are deduced, the definition and criterion of the Noether quasi-symmetric transformation are given, and the exact invariant led directly by the Noether symmetry is obtained. Finally, based upon the concept of high-order adiabatic invariant of a mechanical system, the relationship between the perturbation to the Noether symmetry and the adiabatic invariant after the action of a small disturbance is studied and the conditions that the perturbation of symmetry leads to the adiabatic invariant and its formulation are given. At the end of the paper, two examples are given to illustrate the application of the method and results.