Contact Info
Combinatorics & Optimization
University of Waterloo
Waterloo, Ontario
Canada N2L 3G1
Phone: 519-888-4567, ext 33038
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Monday, April 24, 2023 — 11:30 AM EDT
Title: A Primal-Dual Extension of the Goemans and Williamson Algorithm for Weighted Fractional Cut Cover
| Speaker: | Nathan Benedetto Proenca |
| Affiliation: | University of Waterloo |
| Location: | Please contact Sabrina Lato for Zoom link |
Abstract: A cut in a graph G = (V, E) is a set of edges which has one endpoint in S, for a given subset S of V. The fractional cut-covering number is the optimal value of a linear programming relaxation for the problem of covering each edge by a set of cuts. Beyond its role as part of Šámal's work on cut continuous functions, this graph parameter also arises as the gauge dual of the maximum cut problem.
Friday, April 14, 2023 — 3:30 PM EDT
Title: Sets that Support a Joint Distribution
| Speaker: | Peter Winkler |
| Affiliation: | Dartmouth College |
| Location: | MC 5501 or contact Eva Lee for Zoom link |
Abstract: Given a closed set on the plane and two probability distributions on the real line, when are there random variables with the given distributions whose joint distribution is supported by the given set?
Monday, April 10, 2023 — 11:30 AM EDT
Title: Quantum Algorithms and Mutually Unbiased Bases
| Speaker: | Andrew Jena |
| Affiliation: | University of Waterloo |
| Location: | Please contact Sabrina Lato for Zoom link |
Abstract: Mutually unbiased bases are fundamental to quantum information theory, showing up in quantum key distribution, quantum error correction, and quantum entanglement measures. They likewise might be familiar to algebraic graph theorists, thanks to their connection to equiangular lines and association schemes.
Monday, April 3, 2023 — 3:00 PM EDT
Title: The heroes of digraphs: coloring digraphs with forbidden induced subgraphs
| Speaker: | Alvaro Carbonero |
| Affiliation: | University of Waterloo |
| Location: | MC 5479 |
Abstract: The chromatic number is one of the most studied graph invariants in graph theory. $\chi$-boundedness, for instance, studies the induced subgraphs present in graphs with large chromatic number and small clique number. Neumann-Lara introduced an analog directed version of this graph invariant: the dichromatic number of digraphs.
Monday, April 3, 2023 — 11:30 AM EDT
Title: Four types of integrality on mixed Cayley graphs over abelian groups
| Speaker: | Monu Kadyan |
| Affiliation: | Indian Institute of Technology Guwahati |
| Location: | Please contact Sabrina Lato for Zoom link |
Abstract: A mixed graph is called H-integral (resp. HS-integral) if the eigenvalues of its Hermitian-adjacency matrix (resp. Hermitian-adjacency matrix of second kind) are integers.