The NT seminar takes place on Wednesday at 4pm in McCrea 219.

Here is a campus plan.

October 3:

October 10:

October 17:

October 31:

November 7:

November 14:

November 21:

"A contraction theorem for the largest eigenvalue of a multigraph"

Abstract: Let G be a multigraph with loops, and let e be an edge in G. Let H be the multigraph obtained by contracting along the edge e. Let lambda_G and lambda_H be the largest eigenvalues of G and H respectively. A characterisation will be given of precisely when lambda_H < lambda_G, lambda_H = lambda_G, or lambda_H > lambda_G. If H happens to be a simple graph, then so is G, and the characterisation theorem subsumes those of Hoffman-Smith and Gumbrell for subdivision of edges or splitting of vertices of a graph. (Multi)graph eigenvalues are examples of algebraic integers, and this work was motivated by the study of certain families of algebraic integers.

November 28:

December 5:

December 12:

Spring 2016

Autumn 2015

Spring 2015

Autumn 2014