Algebraic Graph Theory - Chris Godsil

Tuesday, May 31, 2016 3:30 pm - 4:30 pm EDT (GMT -04:00)

Title: Inverses of Trees

Speaker: krystal Guo
Affiliation: University of Waterloo
Room: MC 6486

Abstract: We consider trees whose adjacency matrix are invertible
matrices. A classic result of Godsil gives that the inverses of an
invertible tree T corresponds to a graph which contains T as a
spanning tree. This allows for the characterization of the invertible
trees which attain the minimum and maximum median eigenvalue by Godsil and Zhang & Chang, respectively. We give an alternative proof for the characterization of trees with maximum median eigenvalue and, in doing so, define a poset on the set of invertible trees on 2n vertices.