The C&O department has 36 faculty members and 60 graduate students. We are intensely research oriented and hold a strong international reputation in each of our six major areas:
- Algebraic combinatorics
- Combinatorial optimization
- Continuous optimization
- Cryptography
- Graph theory
- Quantum computing
Read more about the department's research to learn of our contributions to the world of mathematics!
News
Remembering Dominic Welsh
The University of Waterloo community deeply mourns the loss of Professor Dominic Welsh, a distinguished mathematician and a recipient of our honorary doctorate.
Sophie Spirkl receives Sloan Foundation Fellowship
Sophie Spirkl, an assistant professor of Combinatorics and Optimization, has received a prestigious Sloan Research Fellowship from the Alfred P. Sloan Foundation. Spirkl is one of 125 early career researchers in the United States and Canada who received a Fellowship this year.
Karen Yeats awarded renewed Canada Research Chair
Karen Yeats, an associate professor in the Department of Combinatorics and Optimization, has recently been named among the latest cohort of Canada Research Chairs.
Events
Algebraic and Enumerative Combinatorics - Nathan Pagliaroli
Title: Colored unstable map enumeration from random noncommutative geometries
Speaker: | Nathan Pagliaroli |
Affiliation: | Western University |
Location: | MC 5479 |
There will be a pre-seminar presenting relevant background at the beginning graduate level starting at 1pm.
Abstract: The enumeration of maps originates from a series of works by Tutte in the 1960’s. This work later went on to find uses in physics in the enumeration of Feynman diagrammatic expansions of matrix integrals.
In this talk I will discuss how maps with colored edges glued from 2-cells with one or two boundaries arise in recent work in the construction of path integrals over finite dimensional noncommutative spaces. Explicit formulae for the enumeration of such planar maps can be found by solving generalizations of Tutte’s equations. The generating functions of higher genus maps can also be computed from planar map generating functions using a process called Topological Recursion. This talk is based on joint work with Hamed Hessam and Masoud Khalkhali.
C&O Reading Group - Vihan Shah
Title: An Optimal Algorithm for Online Bipartite Matching
Speaker: | Vihan Shah |
Affiliation: | University of Waterloo |
Location: | MC 6029 |
Abstract: We consider the bipartite matching problem in the online setting where vertices on the left arrive in an arbitrary order along with all their edges. Once a vertex arrives, the algorithm has to match the vertex (or can choose to not match it) and this decision cannot be changed later. Karp, Vazirani, and Vazirani give an algorithm for this problem with a competitive ratio of 1-1/e and also show it is optimal.
Tutte Colloquium - Luke Postle
Title: Refined Absorption: A New Proof of the Existence Conjecture
Speaker: | Luke Postle |
Affiliation: | University of Waterloo |
Location: | MC 5501 |
Abstract: The study of combinatorial designs has a rich history spanning nearly two centuries. In a recent breakthrough, the notorious Existence Conjecture for Combinatorial Designs dating back to the 1800s was proved in full by Keevash via the method of randomized algebraic constructions. Subsequently Glock, Kühn, Lo, and Osthus provided an alternate purely combinatorial proof of the Existence Conjecture via the method of iterative absorption. We introduce a novel method of “refined absorption” for designs; in this talk, as our first application of the method we provide a new alternate proof of the Existence Conjecture. Joint work with Michelle Delcourt.