Title: An f-coloring generalization of linear arboricity
Title: Distance-regular graphs with primitive automorphism groups
Title: Bargain hunting in a Coxeter group
Title: Matroids without cliques
| Speaker: | Peter Nelson |
| Affiliation: | University of Waterloo |
| Location: | MC 5501 or contact Eva Lee for Zoom link |
Abstract: The class of graphs that omit some fixed complete graph as a minor is very well-studied; in particular, the densest graphs in the class are known. The analogous question for matroids is just as well-motivated, but seems harder to answer. I will discuss some recent progress in this area, which reduces a bound from doubly exponential to singly exponential. This is joint work with Sergey Norin and Fernanda Rivera Omana.
Title: Edge domination in incidence graphs
Title: Taking limits in Go-diagrams
Title: Rectangle covers and bounding the extension complexity of the correlation polytope
Title: Steiner Cut Dominants
| Speaker: | Volker Kaibel |
| Affiliation: | Otto von Guericke University Magdeburg |
| Location: | MC 5501 or contact Eva Lee for Zoom link |
Abstract: For a subset of terminals T of the nodes of a graph G a cut in G is called a T-Steiner cut if it subdivides T into two non-empty sets. The Steiner cut dominant of G is the Minkowski sum of the convex hull of the incidence vectors of T-Steiner cuts in G and the nonnegative orthant.
Title : A Closure Lemma for tough graphs and Hamiltonian degree conditions
| Speaker: | Cléophée Robin |
| Institution: | Wilfrid Laurier University |
| Location: | MC 5479 |
Abstract: A graph G is hamiltonian if it exists a cycle in G containing all vertices of G exactly once. A graph G is t-tough if, ,for all subsets of vertices S, the number of connected components in G − S is at most |S| / t.
Title: Quasisymmetric varieties, excedances, and bases for the Temperley--Lieb algebra
| Speaker: | Lucas Gagnon |
| Affiliation: | York University |
| Location: | MC 6029 please contact Olya Mandelshtam for Zoom link |
Abstract: This talk is about finding a quasisymmetric variety (QSV): a subset of permutations which (i) is a basis for the Temperley--Lieb algebra TL_n(2), and (ii) has a vanishing ideal (as points in n-space) that behaves similarly to the ideal generated by quasisymmetric polynomials. While this problem is primarily motivated by classical (co-)invariant theory and generalizations thereof, the course of our investigation uncovered a number of remarkable combinatorial properties related to our QSV, and I will survey these as well.