Welcome to Combinatorics and Optimization
Spring 2020 Undergraduate Research Assistantship Program (URA). ***ON-LINE APPICATIONS OPEN November 1, 2019.***
The very successful Tutte's 100th Distinguished Lecture Series has now completed. That success has led to a Tutte Distinguished Lecture once per term. The next lecture will happen in the Spring term.
*Recordings of occurred talks are all available on C&O's YouTube Channel.
New Deadline: February 1, '20
- July 17, 2020
Jochen Koenemann, Kanstantsin Pashkovich and Natig Tofigzade were announced the recipients of the SAGT 2020 Best Paper Award for their paper "Approximating Stable Matchings with Ties of Bounded Size".
- July 1, 2020
The C&O department is very pleased to welcome four new faculty members, Assistant Professors Logan Crew, Stephen Melczer, Oliver Pechenik and Sophie Spirkl.
- June 30, 2020
At the Spring convocation, Jun Yan was awarded an Alumni Gold Medal in recognition of his academic excellence during his undergraduate studies in Combinatorics & Optimization and Pure Mathematics. Jun Yan was also a recipient of the 2020 William Tutte Centenary Scholarship.
- Aug. 17, 2020
Title: State transfer and the size of the graph
Speaker: Gabriel Coutinho Affiliation: Universidade Federal de Minas Gerais Zoom: Contact Soffia Arnadottir
If there is perfect state transfer between two vertices at distance d, how small can the graph be compared to d? This question is motivated by the fact that the known infinite families of graphs admitting state transfer at increasingly large distances are all obtained from graph products, thus their sizes grow exponentially compared to their diameter.
- Aug. 21, 2020
Title: An Algorithmic Reduction Theory for Binary Codes: LLL and more
Joint work with Thomas Debris-Alazard and Wessel van Woerden
Speaker: Léo Ducas Affiliation: Centrum Wiskunde & Informatica (CWI) Zoom: Please email Emma Watson
Lattice reduction is the task of finding a basis of short and somewhat orthogonal vectors of a given lattice. In 1985 Lenstra, Lenstra and Lovasz proposed a polynomial time algorithm for this task, with an application to factoring rational polynomials. Since then, the LLL algorithm has found countless application in algorithmic number theory and in cryptanalysis.
- Aug. 28, 2020
Title: Pure pairs
Speaker: Sophie Spirkl Affiliation: University of Waterloo Zoom: Please email Emma Watson.
A pure pair in a graph G is a pair of subsets A and B of the vertex set such that between A and B, either all edges or no edges are present in G. This concept was first introduced in connected with the Erdos-Hajnal conjecture, but has since developed a life of its own. I will give an overview of results and open questions on pure pairs.
Based on joint work with Maria Chudnovsky, Jacob Fox, Alex Scott, and Paul Seymour.