Introduction to infinite matroids

Series
Graph Theory Seminar
Time
Thursday, September 30, 2010 - 12:05pm for 1 hour (actually 50 minutes)
Location
Skiles 114
Speaker
Luke Postle – Math, GT
Organizer
Robin Thomas
Rota asked in the 1960's how one might construct an axiom system for infinite matroids. Among the many suggested answers were the B-matroids of Higgs. In 1978, Oxley proved that any infinite matroid system with the notions of duality and minors must be equivalent to B-matroids. He also provided a simpler mixed basis-independence axiom system for B-matroids, as opposed to the complicated closure system developed by Higgs. In this talk, we examine a recent paper of Bruhn et al that gives independence, basis, circuit, rank, and closure axiom systems for B-matroids. We will also discuss some open problems for infinite matroids.