The SU(1, 1) propagator as a path integral over noncompact groups

E. A. Kochetov

E. A. Kochetov

M. Böhm, Georg Junker

Applications of group theoretical methods in the path integral formalism of nonrelativistic quantum theory are considered. Analysis of the symmetry of the Lagrangian leads to the expansion of the short time propagator in matrix elements of unitary irreducible representations of the symmetry group. Identification of the coordinates with the group parameters transforms the path integral to integrals over the group manifold. The integration is performed using the orthogonality of the representations. Compact and noncompact rotation groups are considered, where the corresponding path integral is embedded in Euclidean and pseudo-Euclidean spaces, respectively. The unit sphere and unit hyperboloid may either be viewed as the group manifold itself or at least as a group quotient. In the first case Fourier analysis leads to an expansion in group characters. In the second case an expansion in zonal spherical functions is obtained. As examples the groups SO(n), SU(2), SO(n−1,1), and SU(1,1) are explicitly discussed. The path integral on SO(n+m) and SO(n,m) in bispherical coordinates is also treated.

Масуд Чайчиан, Demosthenes Ellinas, Peter Prešnajder

For the real supergroup Osp(1‖2;R), with both its compact and noncompact versions, supercoherent states are introduced with a method close to the one by Perelomov for the even subgroups SU(2) or SU(1,1). These states labeled by a complex c number and Grassmann variable minimize the uncertainty of the quadratic Casimir operator of the group. A path integral formalism is developed for the transition amplitude between supercoherent states for a Hamiltonian linear in the generators of the superalgebra, which leads to a super-Riccati equation. Finally, in the classical limit the canonical equations of motion are derived which involve a generalized super Poisson bracket.

Christopher C. Gerry

E. A. Kochetov

A path integral written in terms of the group theoretic coherent states by using the Kähler structure of the coherent state manifold with the particular emphasis on the boundary-fixing term derivation is considered herein. The path integral for a propagator of the system with Hamiltonian linear in the SU(2)/SU(1,1) generators is shown to be diagonalized by an appropriate motion in the phase space.