The Oberwolfach Problem

Andrea Burgess (UNB Saint John)

The Oberwolfach Problem was posed by Ringel as a seating problem: people attend a conference in Oberwolfach, where the dining room has round tables of sizes (with ). Is it possible to devise a seating plan over successive dinners in which each person sits next to each other person exactly once?

In graph-theoretical terms, the Oberwolfach Problem asks whether, given a 2-factor of order , the complete graph can be decomposed into copies of . In this talk, we present solutions of the Oberwolfach Problem obtained via graceful labellings. This is joint work with Peter Danziger (Ryerson) and Tommaso Traetta (Brescia).

The Unitary Birkhoff-von Neumann theorem

Stijn De Baerdemacker (UNB Fredericton)

Birkhoff has shown that the doubly stochastic matrices can be written as a weighted sum over the permutation matrices of the same dimension. I will show that a similar theorem holds for unitary matrices with equal linesum, and talk about applications in quantum computing.

Musical Guests

• TBA

This is a virtual zoom meeting.  If you would like to attend, please email the organizers for connection details.

[more information about the Math Kitchen Party summer talk series]