Orbifolds, Quantum Cosmology, and Nontrivial Topology

摘要

In order to include nontrivial spatial topologies in the problem of quantumcreation of a universe, it seems to be necessary to generalize the sum overcompact, smooth 4-manifolds to a sum over finite-volume, compact 4-orbifolds.We consider in detail the case of a 4-spherical orbifold with a cone-pointsingularity. This allows for the inclusion of a nontrivial topology in thesemiclassical path integral approach to quantum cosmology, in the context of aRobertson-Walker minisuperspace.