Welcome to Combinatorics and Optimization
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
- Feb. 3, 2021
The Canadian Mathematical Society (CMS) has named Luke Postle as the recipient of the 2021 Coxeter-James Prize for his work in graph theory.
- Jan. 28, 2021
Jodie Wallis (BMath ’93) was a natural fit for Operations Research at the Faculty of Mathematics. “I liked how Operations Research brought together different disciplines and applied directly to business problems,” she affirmed. “That process of taking a problem, considering multiple layers of solutions, and ending up with something that’s elegant and workable in the real world was appealing to me.”
- Jan. 6, 2021
C&O professor David Gosset has published a paper "Classical algorithms for quantum mean values" in Nature Physics.
- Apr. 23, 2021
Title: Robust Interior Point Methods for Key Rate Computation in Quantum Key Distribution
Speaker: Hao Hu Affliliation: University of Waterloo Zoom: Contact Emma Watson
We study semidefinite programs for computing the key rate in finite dimensional quantum key distribution (QKD) problems. Through facial reduction, we derive a semidefinite program which is robust and stable in the numerical computation. Our program avoids the difficulties for current algorithms from singularities that arise due to loss of positive definiteness. This allows for the derivation of an efficient Gauss-Newton interior point approach. We provide provable lower and upper bounds for the hard nonlinear semidefinite programming problem.
- Apr. 26, 2021
Title: A Spectral Moore Bound for Bipartite Semiregular Graphs
Speaker: Sabrina Lato Affiliation: University of Waterloo Zoom: Contact Soffia Arnadottir
The Moore bound provides an upper bound on the number of vertices of a regular graph with a given degree and diameter, though there are disappointingly few graphs that achieve this bound. Thus, it is interesting to ask what additional information can be used to give Moore-type bounds that are tight for a larger number of graphs. Cioaba, Koolen, Nozaki, and Vermette considered regular graphs with a given second-largest eigenvalue, and found an upper bound for such graphs.