Graphs and Matroids Seminar - Rong Chen

Title: The 8-connected excluded minors for the class of quasi-graphic matroids

Abstract:

The class of quasi-graphic matroids, recently introduced by Geelen, Gerards, and Whittle, is minor closed and contains both lifted-graphic matroids and frame matroids, each of which generalises the class of graphic matroids. We recently prove that the only 8-connected excluded minors for the class of quasi-graphic matroids are the two uniform matroids with seven elements of rank three and four. In this talk, I will introduce some new strategies used in this paper.