Aarhus University Seal / Aarhus Universitets segl

Triangulations of surfaces, 2 x 2 matrices, and spaces of immersed ellipses

Chris Judge
(Department of Mathematics, Indiana University)
Thursday, 17 June, 2010, at 16:15-17:15, in Aud. D2 (1531-119)
Flat surfaces with cone points are central objects in Teichmueller theory. Such surfaces have canonical polygonal cell decompostions called Delaunay partitions. For the generic flat surface, this decomposition is a triangulation. The natural action of SL(2, R) on the flat surfaces induces diagonal flipping of the triangulations. We will show how diagonal flipping can be understood in terms of immersed ellipses that meet 5 or more cone points.
Organised by: CTQM/QGM
Contact person: Jørgen Ellegaard Andersen