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

## Three C&O faculty win Outstanding Performance Awards

The awards are given each year to faculty members across the University of Waterloo who demonstrate excellence in teaching and research.

## Prof. Alfred Menezes is named Fellow of the International Association for Cryptologic Research

The Fellows program, which was established in 2004, is awarded to no more than 0.25% of the IACR’s 3000 members each year and recognizes “outstanding IACR members for technical and professional contributions to cryptologic research.”

## C&O student Ava Pun receives Jessie W. H. Zou Memorial Award

She received the award in recognition of her research on simulating virtual training environments for autonomous vehicles, which she conducted at the start-up Waabi.

## Events

## Algebraic & Enumerative Combinatorics - Laura Pierson

**Title: **Two variations of the chromatic symmetric function

Speaker: |
Laura Pierson |

Affiliation: |
University of Waterloo |

Location: |
MC 5479 |

**Abstract: **The /chromatic symmetric function/ is a symmetric function generalization of the chromatic polynomial that encodes the ways to color a graph such that no two adjacent vertices get the same color. We will discuss two different analogues of the chromatic symmetric function: a K-theoretic analogue called the /Kromatic symmetric function/, and a categorification called the /chromatic symmetric homology/. We show that certain properties of a graph can be recovered given its Kromatic symmetric function, and we give some formulas for special cases of the chromatic symmetric homology.

## Tutte Colloquium - Paul Seymour

**Title: **Nearly-linear stable sets

Speaker: |
Paul Seymour |

Affiliation: |
Princeton University |

Location: |
QNC 0101 |

**Abstract: **The Gyárfás-Sumner conjecture says that for every forest 𝐻 and complete graph 𝐾, there exists 𝑐 such that every {𝐻,𝐾}-free graph (that is, containing neither of 𝐻,𝐾 as an induced subgraph) has chromatic number at most 𝑐. This is still open, but we have proved that every {𝐻,𝐾}-free graph 𝐺 has chromatic number at most |𝐺|^{o(1)}.

## Tutte Colloquium - Carla Groenland

**Title: **Tight bounds for reconstructing graphs from distance queries

Speaker: |
Carla Groenland |

Affiliation: |
TU Delft |

Location: |
MC 5501 |

**Abstract: **Suppose you are given the vertex set of a graph and you want to discover the edge set. An oracle can tell you, given two vertices, what the distance is between these vertices in the graph. (For example, in a computer network, this would represent the minimum number of communication links needed to send a message from one computer to another.) Based on the answer, you may select the next query. The (labelled) graph is reconstructed when there is a single edge set compatible with the answers. How many queries are needed, in the worst case? The question becomes interesting for bounded degree graphs. We provide tight bounds for various classes of graphs, improving both the lower and upper bound, in both the randomized and deterministic setting.