May 9, 2019
Sandpile group of graphs and digraphs
Date: May 9, 2019 |
1:30 pm –
3:30 pm
Speaker:
Lilla Tóthmérész, Eötvös Loránd University, Budapest
Location: Big Seminar room Ground floor / Office Bldg West (I21.EG.101)
I will talk about the sandpile group of finite graphs and directed graphs. I will state the Riemann-Roch theorem for graphs (due to Baker-Norine), say what can be known about the case of directed graphs, and how these things are connected to feedback arc sets. (This part is joint work with Blint Hujter.)
I will also talk about a very nice connection between sandpile groups of ribbon graphs and planarity: By Chan-Church-Grochow and Baker-Wang, certain actions of the sandpile group of a ribbon graph on the spanning trees are canonical if and only if the ribbon structure is planar. With Tams Klmn and Seunghun Lee we gave a canonical definition for this action in the planar case.
I will also talk about a very nice connection between sandpile groups of ribbon graphs and planarity: By Chan-Church-Grochow and Baker-Wang, certain actions of the sandpile group of a ribbon graph on the spanning trees are canonical if and only if the ribbon structure is planar. With Tams Klmn and Seunghun Lee we gave a canonical definition for this action in the planar case.
