Generalized Bloch analysis and propagators on Riemannian manifolds with a discrete symmetry
arXiv:0802.4235 · doi:10.1063/1.2898484
Abstract
We consider an invariant quantum Hamiltonian in the space based on a Riemannian manifold with a countable discrete symmetry group . Typically, is the universal covering space of a multiply connected Riemannian manifold and is the fundamental group of . On the one hand, following the basic step of the Bloch analysis, one decomposes the space over into a direct integral of Hilbert spaces formed by equivariant functions on . The Hamiltonian decomposes correspondingly, with each component being defined by a quasi-periodic boundary condition. The quasi-periodic boundary conditions are in turn determined by irreducible unitary representations of . On the other hand, fixing a quasi-periodic boundary condition (i.e., a unitary representation of ) one can express the corresponding propagator in terms of the propagator associated to the Hamiltonian . We discuss these procedures in detail and show that in a sense they are mutually inverse.