Future students

Friday, October 4, 2019 3:30 pm - 3:30 pm EDT (GMT -04:00)

Tutte Colloquium - Bruce Richter

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.

Thursday, October 3, 2019 4:00 pm - 4:00 pm EDT (GMT -04:00)

Graphs and Matroids Seminar - Lise Turner

Title: 

Speaker: Lise Turner
Affiliation: University of Waterloo
Room: MC 5501

Abstract:

There are several different notions of what it means for a graph to converge. One popular notion for sparse graphs is Benjamini-Schramm convergence which focuses on local properties of the graphs.

Friday, October 4, 2019 1:00 pm - 1:00 pm EDT (GMT -04:00)

Combinatorial Optimization Reading Group - Ishan Bansal

Title: Greedy Heuristic for Maximizing Submodular Set Functions

Speaker: Ishan Bansal
Affiliation: University of Waterloo
Room: MC 5417

Abstract:

Several hard combinatorial optimization problems can be posed in the following framework: maximize a submodular function over its domain subject to a cardinality constraint.

Thursday, October 3, 2019 3:00 pm - 3:00 pm EDT (GMT -04:00)

Algebraic Combinatorics Seminar - David Wagner

Title: Discrete diffusion on graphs and real hyperplane arrangements

Speaker: David Wagner
Affiliation: University of Waterloo
Room: MC 6483

Abstract:

In 2016, Duffy et al. introduced the following process on a graph.  Initially, each vertex has some integer number of ``chips'' placed there (possibly negative). 

Thursday, September 26, 2019 1:00 pm - 1:00 pm EDT (GMT -04:00)

Algebraic Graph Theory Seminar - Chris Godsil

Title: LP bounds and the addition formula

Speaker: Chris Godsil
Affiliation: University of Waterloo
Room: MC 5479

Abstract:

I will show how we can derive useful bounds on the size of codes and designs, using linear programming and the addition formula.

Thursday, September 26, 2019 3:30 pm - 3:30 pm EDT (GMT -04:00)

Algebraic Combinatorics Seminar - Karen Yeats

Title: Chord diagrams, generating functions, and qft

Speaker: Karen Yeats
Affiliation: University of Waterloo
Room: MC 5417

Abstract:

I'll talk about some joint work with Julien Courtiel where some nice enumerative combinatorics tells us something about how gauge theories are such special quantum field theories.

Thursday, September 19, 2019 1:00 pm - 1:00 pm EDT (GMT -04:00)

Algebraic Graph Theory Seminar - Chris Godsil

TitleOrthogonal Polynomials and the Addition Formula

Speaker: Chris Godsil
Affiliation: University of Waterloo
Room: MC 5479

Abstract:

Many questions about designs and codes in the unit sphere can be reduced to questions about members of a family of orthogonal polynomials, the so-called Gegenbauer polynomials.

Friday, September 20, 2019 3:30 pm - 3:30 pm EDT (GMT -04:00)

Tutte Colloquium - Douglas Stebila

Title: Undermining key exchange

Speaker: Douglas Stebila
Affiliation: University of Waterloo
Room: MC 5501

Abstract:

There are many ways to undermine systems that rely on cryptography. An attacker could of course try to find flaws in the hardware and software implementing the system, or find mathematical weaknesses in the cryptographic algorithms.