New lift matroids for gain graphs

Series
Graph Theory Seminar
Time
Tuesday, September 20, 2022 - 3:45pm for 1 hour (actually 50 minutes)
Location
Skiles 005
Speaker
Zach Walsh – Georgia Tech – zwalsh6@gatech.eduhttps://www.zachwalsh.math.gatech.edu/index.html
Organizer
Tom Kelly

Given a graph G with edges labeled by a group, a construction of Zaslavsky gives a rank-1 lift of the graphic matroid M(G) that respects the group-labeling. For which finite groups can we construct a rank-t lift of M(G) with t > 1 that respects the group-labeling? We show that this is possible if and only if the group is the additive subgroup of a non-prime finite field. We assume no knowledge of matroid theory.