J. Louko et Dm. Marolf, THE SOLUTION SPACE OF 2-X-T2 IN WITTEN CONNECTION FORMULATION(1 GRAVITY ON R), Classical and quantum gravity, 11(2), 1994, pp. 311-330
We investigate the space M of classical solutions of Witten's formulat
ion of 2 + 1 gravity on the manifold R x T2. M is connected, unlike th
e spaces of classical solutions in the cases where T2 is replaced by a
higher genus surface. Although M is neither Hausdorff nor a manifold.
removing from M a set of measure zero yields a manifold which is natu
rally viewed as the cotangent bundle over a non-Hausdorff base space B
. We discuss the relation of the various parts of M with spacetime met
rics, and various possibilities of quantizing M. There exist quantizat
ions in which the exponentials of certain momentum operators, when ope
rating on states whose support is entirely on the part of B correspond
ing to conventional spacetime metrics, give states whose support is en
tirely outside this part of B. Similar results hold when the gauge gro
up SO0(2, 1) is replaced by SU(1, 1).