Abstract: A graph (think: a network composed of vertices/nodes and edges/connections between them) is called planar if it can be drawn in the plane without any of the edges crossing. For graphs which are not planar, one often asks for the minimal number of crossings, the crossing number. Finding crossing numbers for specific graphs is a very hard problem. Not even for the "standard" cases of complete graphs and complete bipartite graphs, the numbers are known. I will talk about recent approaches to find better bounds for these two classical problems.

Seminar is hybrid. So Zoom + in person is OK. Speaker will be in-person. Please contact mathstats-staff@ucdenver.edu for Zoom link.