- Combinatorics Seminar
- Wednesday, September 30, 2020 - 15:30 for 1 hour (actually 50 minutes)
- https://bluejeans.com/751242993/PASSWORD (To receive the password, please email Lutz Warnke)
- Alex Mcdonough – Brown University
Traditionally, the sandpile group is defined on a graph and the Matrix-Tree Theorem says that this group's size is equal to the number of spanning trees. An extension of the Matrix-Tree Theorem gives a relationship between the sandpile group and bases of an arithmetic matroid. I provide a family of combinatorially meaningful maps between these two sets. This generalizes a bijection given by Backman, Baker, and Yuen and extends work by Duval, Klivans, and Martin.
Please note the unusual time/day.