Higher Topologies in 2+1-Gravity
  I argue that the first-order formalism recently found to describe classical 2+1-Gravity with matter, is also able to include higher topologies. The present gauge, which is conformal with vanishing York time, is characterized by an analytic mapping from single-valued coordinates to Minkowskian ones. In the torus case, this mapping is based on four square-root branch points, whose location is related to the modulus, which has a well defined time dependence. In the general case, it is connected with the hyperelliptic representation of Riemann surfaces. 
Marcello Ciafaloni (Dipartimento di Fisica, Universit\`a di Firenze   and I.N.F.N., Sezione di Firenze, Italy)