Abstract
In the talk will be discussed the Voronoi's theory of perfect lattices in an Euclidian space of the dimension n,describing a nice triangulation of the classifying space for the group SL(n,Z).
Perfect lattices give local maxima of density for the corresponding sphere packings.Spherical designs are combinatorial structures important in applied mathematics.In the talk there will be considered interrelations of these to
topics.In some cases the interralation can be explained by modular forms.
Contact person:Jørgen Ellegaard Andersen.