Contact Info
Combinatorics & Optimization
University of Waterloo
Waterloo, Ontario
Canada N2L 3G1
Phone: 519-888-4567, ext 33038
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Thursday, August 15, 2019 2:30 PM EDT
Title: Upsetting Matrices
| Speaker: | Chris Godsil |
| Affiliation: | University of Waterloo |
| Room: | MC 5479 |
Abstract:
If $A$ and $P$ are $n\times n$ matrices and the entries of $B$ are small, we may view $A+B$ as a perturbation of $A$, and expect that the spectral properties of $A+B$ should be related to those of $A$.
Thursday, August 8, 2019 2:30 PM EDT
Title: Continuous Quantum Walks
| Speaker: | Soffia Arnadottir |
| Affiliation: | University of Waterloo |
| Room: | MC 5479 |
Abstract:
Continuous quantum walks are of considerable interest in quantum physics and quantum computing.
Tuesday, August 6, 2019 3:30 PM EDT
Title: Feynman graphs, ribbon graphs and tensor graphs
| Speaker: | Adrian Tanasa |
| Affiliation: | Université de Bordeaux |
| Room: | MC 5479 |
Abstract:
In this talk I will define the so-called Feynman graphs, which are a particular class of graphs appearing in quantum field theory.
Friday, August 2, 2019 3:30 PM EDT
Title: Optimization and Cryptography in Generalized Physical Theories
| Speaker: | Jamie Sikora |
| Affiliation: | Perimeter Institute |
| Room: | MC 5501 |
Abstract:
In this talk, I will discuss three important cryptographic tasks in the quantum and post-quantum world. I will discuss the impossibility of bit-commitment and coin-flipping, and also the possibility of physically unforgeable money in the framework of Generalized Physical Theories (GPTs).
Friday, August 2, 2019 1:00 PM EDT
Title: Stable marraige with general preferences
| Speaker: | Matthew Louis Gerstbrein |
| Affiliation: | University of Waterloo |
| Room: | MC 5479 |
Abstract:
This week, we discuss a generalization of the standard stable marriage problem, in which one side has a complete, totally ordered, strict preference list while the other has preferences given in terms of arbitrary binary relations.
Thursday, August 1, 2019 3:30 PM EDT
Title: Counting subdivergence-free gluing of trees
| Speaker: | Clair Dai |
| Affiliation: | University of Waterloo |
| Room: | MC 5417 |
Abstract:
If we take two rooted trees with the same number of leaves and form a graph by gluing the leaves of one tree to the other, then we say the graph is subdivergence-free if no 2-edge cut have been generated.
Thursday, August 1, 2019 3:30 PM EDT
Title: The combinatorics of nearest and furthest values
| Speaker: | Lily Wang |
| Affiliation: | University of Waterloo |
| Room: | MC 5417 |
Abstract:
A classical problem asks us to find, for each element $A[i]$ of an array of integers, the position of the nearest smallest element.
Thursday, August 1, 2019 3:30 PM EDT
Title: Bijections among symmetric tableaux via folding and mixed insertion
| Speaker: | Yuval Ohapkin |
| Affiliation: | University of Waterloo |
| Room: | MC 5417 |
Abstract:
A standard Young tableau with entries $-M < \cdots -1 < 1 < \cdots < M$ can be "folded" by performing certain conversions and rectifications in sequence.
Thursday, August 1, 2019 2:30 PM EDT
Title: Non-Commutative Algebras and Graphs
| Speaker: | Chris Godsil |
| Affiliation: | University of Waterloo |
| Room: | MC 5479 |
Abstract:
I will discuss some of the non-commutative algebras that arise naturally in graph theory.