Time

Feb 21 2006 - 4:30pm

Location

SM 1042

Speaker

Tim Riley (Cornell University)

Seminar Website

http://www.math.ohio-state.edu/~jlafont/TopSched.html

Abstract

In 2003 I gave a talk at Ohio State in which I described a graph theoretic question concerning duality and the diameters of spanning trees in planar graphs. In this talk I will explain recent work with W.P. Thurston answering this question. Also, I will discuss the significance the answer has for problems of Gromov and Stalling concerning group theoretic invariants (filling functions) that arise from the study of combinatorial homotopy discs (van Kampen diagrams) filling loops in Cayley 2-complexes.