Royal Holloway - Pure Mathematics Seminar


The PM-seminar takes place on Wednesday at 2pm in McCrea 219.
Here is a campus plan.


September 26: Steven Galbraith (Auckland)

"Supersingular isogeny graphs and applications"

Abstract: The graph of isogenies of supersingular elliptic curves has many
applications in computational number theory and public key
cryptography.  I will present some of these applications and I will also
discuss some open problems.


October 3: Waltraud Lederle (Zurich)

"Almost automorphism groups of trees and topological full groups"

Abstract: We will introduce the concepts mentioned in the title, explain why they
are interesting and show a connection between them. Thereby we will see examples
of simple locally compact groups without lattices; finitely generated, simple amenable
groups and the famous Higman-Thompson groups.


October 10: Mark Grant (Aberdeen)

"An equivariant Eilenberg-Ganea Theorem"
 
Abstract: There are (at least) 3 competing notions of "dimension" for discrete groups:
cohomological dimension, geometric dimension (the smallest dimension of a classifying
space), and Lusternik-Schnirelmann category (of a classifying space). Theorems of
Eilenberg-Ganea and Stallings and Swan from the 1950’s and 60's imply that these all
coincide, except for the possible existence of a group with cat=cd=2 and gd=3.
 
I will discuss equivariant generalisations of these theorems to the setting of groups with
operators. The statements involve Bredon cohomological dimension with respect to families
of subgroups, which I'll define during the talk.
 

October 17: Ian Leary (Southampton) !!at 4pm
in McCrea 219!!

"CAT(0) groups need not be biautomatic"

Abstract: Ashot Minasyan and I construct groups that establish the result in the title,
resolving a question that  has been around for almost 30 years.  I will start  by explaining
the phrases `CAT(0)' and `biautomatic'.  After that I will talk about our groups and why
they have the properties that we claim. 


October 18: Victor Moreno (Royal Holloway)  at 4pm in Munro Fox Lecture Theatre
(!!note change of day, time and venue!!)

"Classifying spaces for chains of families of subgroups"

 
October 31: Arno Fehm (Dresden) !!at 2.30pm in McCrea 219!!


November 7: Jessica Banks (Bristol)

"Knots (and surfaces)"

Abstract: We will consider some questions in classical knot theory, and see how surfaces
play a part. In particular, we will look at how knot theory compares with the physical
world, and how hard it is to untangle a knot.


November 14: Xin Li (Queen Mary)

November 21: Evgeny Khukhro (Lincoln)

November 28: Krystal Guo (Bruxelles)

December 5: Vincent Jansen (Royal Holloway)

December 12: Laura Ciobanu (Heriott-Watt)



Previous Pure Mathematics Seminars