Antonio Costa, 5 mai 2009, 11h15, CM 113

Abstract: The moduli space M_{g} of compact Riemann surfaces of genus g has the structure of a complex orbifold since it is the quotient of the Teichmüller space by the discontinuous action of the mapping class group. The set of singular points for the orbifold M_{g} is called the branch locus B_{g}. In this talk we present some new contributions in the understanding of the topology of the branch locus, more concretely about its connectedness and the existence of some connected components of given dimension.