Classical foundations for a quantum theory of time in a two-dimensional spacetime.

摘要

We consider the set of all spacelike embeddings of the circle S1 into a spacetime R1 x S1 with a metric globally conformal to the Minkowski metric. We identify this set and the group of conformal isometries of this spacetime as quotients of semidirect products involving diffeomorphism groups and give a transitive action of the conformal group on the set of spacelike embeddings. We provide results showing that the group of conformal isometries is a topological group and that its action on the set of spacelike embeddings is continuous. Finally, we point out some directions for future research.