Complete sets of invariants for classical and quantum systems

Willard Miller (miller@ima.umn.edu)
(Joint work with E.G. Kalnins, J. Kress and G. Pogosyan)
University of Minnesota
School of Mathematics
127 Vincent Hall 206 Church St. SE
Minneapolis, MN 55455 USA

Abstract

We consider the general problem of determining exactly when a classical Hamiltonian H in n dimensions admits a constant of the motion that is polynomial in the momenta. If the associated Hamilton-Jacobi equation admits an orthogonal separation of variables, then it is possible to generate algorithmically a canonical basis Q, P where P_1=H, P_2, ..., P_n are the other 2nd-order constants of the motion associated with the separable coordinates, and {Q_i,Q_j}={P_i,P_j}=0, {Q_i,P_j}=\delta_{ij}. The 2n-1 functions Q_2,... Q_n,P_1,...,P_n form a basis for the invariants. We show how to determine for exactly which spaces and potentials the invariant Q_j is a polynomial in the original momenta.