Royal Holloway - Number Theory Seminar

The NT seminar takes place on Wednesday at 4pm in McCrea 219.
Here is a campus plan.

October 3: Rainer Dietmann (Royal Holloway)

October 10: Jake Massimo (Royal Holloway)

October 17:
Ian Leary (Southampton)

October 31: Arno Fehm (Dresden)

November 7: Reynold Fregoli
(Royal Holloway)
November 14: Eamonn Postlethwaite (Royal Holloway)

November 21:
James McKee  (Royal Holloway):

"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 2018

Autumn 2017

Spring 2017

Summer 2016

Spring 2016

Autumn 2015

Spring 2015

Autumn 2014