Weak Separation and Plabic Graphs on the Annulus
MATH TABLE
When: September 30, 2026
5:00 pm - 6:00 pm
Where: Science Center 507
Address:
1 Oxford Street, Cambridge, MA 02138, United States
Speaker: Iz Chen - Harvard
Weak separation is a combinatorial criterion that was first defined using marked boundary points on a disk. Oh, Postnikov, and Speyer showed that maximal collections of pairwise weakly separated k-subsets on a disk coincide with the face labels of a class of planar bipartite (plabic) graphs drawn inside a disk. In this talk, we define weak separation on an annulus and discuss properties of annular weakly separated collections. We introduce special classes of plabic graphs whose face labels are maximal annular collections.