2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/52701Three dimensional quantum gravity with torus universe, T^2xR topology is reformulated as the motion of a relativistic point particle moving in an Sl(2,Z) orbifold of flat Minkowski spacetime. The latter is precisely the three dimensional Milne Universe studied recently by Russo as a background for Strings. We comment briefly on the dynamics and quantization of the model.8 pages, invited contribution to DeserfestHigh Energy Physics - Theorytext