Yassin Chandran

These are notes on the open problem session run by Priyam Patel and Nicholas Vlamis for the infinite-type surfaces group at the 2021 Nearly Carbon Neutral Geometric Topology conference organized by Elizabeth Field, Hannah Hoganson, and Marissa Loving. The notes have been typed by Yassin Chandran.

Given a natural number k and an orientable surface S of finite type, define the k-curve graph to be the graph with vertices corresponding to isotopy classes of essential simple closed curves on S and with edges corresponding to pairs of such curves admitting representatives that intersect at most k times. We prove that the automorphism group of the k-curve graph of a surface S is isomorphic to the extended mapping class group for all k sufficiently small with respect to the Euler characteristic of S. We prove the same result for the so-called systolic complex, a variant of the curve graph whose complete subgraphs encode the intersection patterns for any collection of systoles with respect to a hyperbolic metric. This resolves a conjecture of Schmutz Schaller.