Algebraic Graph Theory - William Linz

Monday, June 12, 2023 11:30 am - 11:30 am EDT (GMT -04:00)

Title: L-systems and the Lovasz number

Speaker: William Linz
Affiliation: University of South Carolina
Location: Please contactSabrina Latofor Zoom link

Abstract: For positive integers n and k, an L-system is a collection of k-uniform subsets of a set of size n whose pairwise intersection sizes all lie in in the set L. The maximum size of an L-system is equal to the independence number of a certain union of graphs in the Johnson scheme. The Lovasz number is a semidefinite programming approximation of the independence number of a graph. In this talk, we survey the relationship between the maximum size of an L-system and the Lovasz number, illustrating examples both where the Lovasz number is a good approximation and where it is a bad approximation.