Contact Info
Combinatorics & Optimization
University of Waterloo
Waterloo, Ontario
Canada N2L 3G1
Phone: 5198884567, ext 33038
PDF files require Adobe Acrobat Reader.
Sun  Mon  Tue  Wed  Thu  Fri  Sat 

29

30

31

1

2

3

4








5

6

7

8

11








12

13

14

15

18








19

20

21

22

25








26

27

28

29

1







Title: Periodicity in Quantum Walks
Speaker: Chris Godsil Affiliation: University of Waterloo Room: MC 5417Abstract:
Despite the title, quantum walks are, in general, not periodic. However they are, in general, periodic to any desired degree of accuracy.
Title: Beating 3/2 for Approximating TSP in the HalfIntegral Case
Speaker: Logan Grout Affiliation: University of Waterloo Room: MC 5417Abstract:
In 2013, Schalekamp, Williamson, and van Zuylen conjectured that the integrality gap for the Subtour Polytope was attained on its halfintegral vertices.
Title: Covers of Complete Bipartite Graphs
Speaker: Chris Godsil Affiliation: University of Waterloo Room: MC 5417Abstract:
I will discuss antipodal distanceregular covers of complete bipartite graphs $K_{n,n}$. The index of such a cover is at most $n$.
Title: Electrical networks, random spanning trees, and matroids
Speaker: David Wagner Affiliation: University of Waterloo Room: MC 5417Abstract:
This is a reprise of a survey talk I gave at the East Coast Combinatorics Conference in August 2019, and a variation of one I gave in the graphs and matroids seminar last year.
Title: The Capacitated Survivable Network Design Problem
Speaker: Ishan Bansal Affiliation: University of Waterloo Room: MC 5417Abstract:
The Capacitated Survivable Network Design Problem or CapSNDP models a network reinforcement problem where the network designer wants to find a minimumcost set of reinforcements that protects the network from an adversary.
Title: Some places matroids appear in quantum field theory and some places I would like them to
Speaker: Karen Yeats Affiliation: University of Waterloo Room: MC 5417Abstract:
I will discuss some places matroids have appeared in my work in quantum field theory, including some older work on numerator structure with Dirk Kreimer and some work in progress with Iain Crump on period identities.
Title: Uniformly generate graphs with given degrees rapidly
Speaker: Jane Gao Affiliation: University of Waterloo Room: MC 5479Abstract:
I will survey the research on exact/approximate uniform generation of graphs with prescribed degrees.
Title: On the Strong Nine Dragon Tree Conjecture
Speaker: Ben Moore Affiliation: University of Waterloo Room: MC 5417Abstract:
NashWilliams forest covering theorem says that a graph decomposes into $k$ forests if and only if it has fractional arboricity at most $k$. In 2012 Mickeal Montassier, Patrice Ossona de Mendez, Andre Raspaud, and Xuding Zhu proposed a significant strengthening of NashWilliams Theorem, called the Strong Nine Dragon Tree Conjecture.
Title: Random PatternAvoiding Permutations
Speaker: Neal Madras Affiliation: York University Room: MC 5417Abstract:
A "pattern of length k" is simply a permutation of {1,..,k}. This pattern is said to be contained in a permutation of {1,...,N} (for N>k) if there is a subsequence of k elements of the (long) permutation that appears in the same relative order as the pattern.
Title: Excluding a ladder
Speaker: Paul Wollan Affiliation: Sapienza Università di Roma Room: MC 5479Abstract:
A folklore result says that if a graph does not contain the path of length k as a subgraph, then it has treedepth at most k.
Title: Network Design $s$$t$ Effective Resistance
Speaker: Hong Zhou Affiliation: University of Waterloo Room: MC 5417Abstract:
We consider a problem of designing a network with small $s$$t$ effective resistance. In the problem, we are given an undirected graph $G=(V,E)$, two designated vertices $s,t \in V$, and a budget $k$.
Combinatorics & Optimization
University of Waterloo
Waterloo, Ontario
Canada N2L 3G1
Phone: 5198884567, ext 33038
PDF files require Adobe Acrobat Reader.
The University of Waterloo acknowledges that much of our work takes place on the traditional territory of the Neutral, Anishinaabeg and Haudenosaunee peoples. Our main campus is situated on the Haldimand Tract, the land granted to the Six Nations that includes six miles on each side of the Grand River. Our active work toward reconciliation takes place across our campuses through research, learning, teaching, and community building, and is centralized within our Office of Indigenous Relations.