Title: Boundary measurement and sign variation in real projective space
| Speaker: | John Machacek |
| Affiliation: | York University |
| Room: | MC 5417 |
Abstract:
Title: Discrete quantum walks, embeddings and designs
| Speaker: | Harmony Zhan |
| Affiliation: | York University |
| Room: | MC 5479 |
Abstract:
We construct a quantum walk from an embedding of a graph.
Title: Quantum Colouring and Derangements
| Speaker: | Chris Godsil |
| Affiliation: | University of Waterloo |
| Room: | MC 5479 |
Abstract:
Work in quantum information has lead to the introduction of quantum colourings.
Title: On the depth of cutting planesOn the depth of cutting planes
| Speaker: | Laurent Poirrier |
| Affiliation: | University of Waterloo |
| Room: | MC 5501 |
Abstract:
We tackle one of the most important open problems in computational integer programming: cut selection.
For four decades, cutting planes were believed to be useful only for structured combinatorial problems. This changed in 1995 when Balas, Ceria and Cornuéjols showed that Gomory cuts could helpfully strengthen the formulation of general integer programming problems. Since then, many other cut generation techniques have been developed, but their practical success has been moderate at best.
Title: A Pseudoforest Analogue of the Strong Nine Dragon Tree Conjecture
| Speaker: | Logan Grout |
| Affiliation: | University of Waterloo |
| Room: | MC 5501 |
Abstract:
In 2016, Jiang and Yang proved the Nine Dragon Tree Conjecture, a strengthening of the classical arboricity result of Nash-Williams (1964). On the way to developing this proof, Fan, Lim Song, and Yang proved an analogous result for decomposing graphs into pseudoforests, which is a strengthening of Hakimi’s Theorem.
Title: Maximizing a Monotone Submodular Function subject to a Matroid Constraint
| Speaker: | Justin Toth |
| Affiliation: | University of Waterloo |
| Room: | MC 5417 |
Abstract:
Based on the paper by Calinescu, Chekuri, Pál, and Vondrák of the same title. We will study a randomized $(1-\frac{1}{e})$-approximation algorithm for the titular problem.
Title: Scattering amplitudes and associahedra
| Speaker: | Hugh Thomas |
| Affiliation: | UQAM |
| Room: | MC 5417 |
Abstract:
The classic approach to scattering amplitudes sums a contribution from a (potentially very large) number of Feynman diagrams.
Isaac Ellmen (BMath ’19) and his co-founder Danielle Rose (BSc ‘19, University of Guelph) were one of the recipients of the grand prize of direct equity investments worth $50,000 in the Velocity Fund Competition in Toronto on September 19, 2019. SquidBio was started in November of 2018 and later joined Velocity Science.
Title: Extending drawings of K(n) to pseudolines and pseudocircles
| Speaker: | Bruce Richter |
| Affiliation: | University of Waterloo |
| Room: | MC 5501 |
Abstract:
In the early part of the 21st century, it was shown that the number of crossings in a straight-line drawing of K(n) is at least the number H(n), which is conjectured to be the crossing number of K(n). In fact, it is now known that, for n at least 10, the inequality is strict.
Title: Type II Matrices
| Speaker: | Ada Chan |
| Affiliation: | York University |
| Room: | MC 5479 |
Abstract:
In 1867, Sylvester defined an {\sl inverse orthogonal matrix} as an $n\times n$ complex matrix $W$ satisfying