Seminar

Friday, September 14, 2018 3:30 pm - 3:30 pm EDT (GMT -04:00)

Tutte Colloquium - Michelle Delcourt

Title: Rapid mixing of Glauber dynamics for colorings below Vigoda’s 11/6 threshold 

Speaker: Michelle Delcourt
Affiliation: University of Waterloo
Room: MC 5501

Abstract:

A well-known conjecture in computer science and statistical physics is that Glauber dynamics on the set of k-colorings of a graph G on n vertices with maximum degree Δ is rapidly mixing for k ≥ Δ+2.

Friday, September 7, 2018 3:30 pm - 3:30 pm EDT (GMT -04:00)

Tutte Colloquium - Sebastian Cioaba

Title: The smallest eigenvalues of Hamming, Johnson and other graphs

Speaker: Sebastian Cioaba
Affiliation: University of Delaware
Room: MC 5501

Abstract:

The smallest eigenvalue of graphs is closely related to other graph parameters such as the independence number, the chromatic number or the max-cut.

Thursday, August 16, 2018 11:30 am - 11:30 am EDT (GMT -04:00)

Algebraic Combinatorics Seminar

Title: Counting Partitions Inside a Rectangle

Speaker: Steve Melczer
Affiliation: University of Pennsylvania
Room: MC 6486

Abstract:

The study of integer partitions is a classic subject with applications ranging from number theory to representation theory and combinatorics.

Tuesday, July 17, 2018 3:00 pm - 3:00 pm EDT (GMT -04:00)

Joint Pure Math/C&O Colloquium - Justin Toth

Title: Using Linear Algebra to do Matching Theory

Speaker: Justin Toth
Affiliation: University of Waterloo
Room: MC 5501

Abstract:

A matching in a graph is a set of edges with each vertex contained in at most one edge. A perfect matching is a matching in which each vertex is contained in some edge.

Thursday, July 12, 2018 1:30 pm - 1:30 pm EDT (GMT -04:00)

Algebraic Graph Theory Seminar

Title: Periodicity on Oriented Graphs by way of Transcendental Number Theory

Speaker: Sabrina Lato
Affiliation: University of Waterloo
Room: MC 6486

Abstract: Using the adjacency matrix of a graph, it is straightforward to show that perfect state transfer between two vertices at some time t implies that both vertices will be periodic at time 2t.

Thursday, July 12, 2018 3:30 pm - 3:30 pm EDT (GMT -04:00)

Graphs and Matroids Seminar

Title: Gaps in the crossing numbers of drawings of the complete graph

Speaker: Bruce Richter
Affiliation: University of Waterloo
Room: MC 5479

Abstract: In the late 1990’s, a 5-author manuscript circulated proving the existence of intervals of integers that connot occur as the crossing number of a “good” drawing of the complete graph.