12–15 Oct 2026
Palazzo del Castelletto
Europe/Rome timezone

Almost planar finitely presented groups

14 Oct 2026, 14:30
1h
Aula Dini (Palazzo del Castelletto)

Aula Dini

Palazzo del Castelletto

Via del Castelletto, 11, 56126 Pisa PI

Speaker

Joseph MacManus (University of Bristol)

Description

Following Benjamini-Schramm, a graph is called 'almost planar' if it can be drawn in the plane such that every edge crosses at most a bounded number of edges, and a finitely generated group is called an 'almost planar group' if its Cayley graphs are almost planar graphs. Despite being a relatively well-studied class, the only known examples of such groups are those which virtually admit a planar Cayley graph. Recently, it was conjectured by Georgakopoulos-Papasoglu that these are indeed the only examples, suggesting a robust rigidity result. In this talk, I will contextualise and report progress on this conjecture, settling it within the class of finitely presented groups. This talk is based on joint work with John Mackay and Davide Spriano.

Author

Joseph MacManus (University of Bristol)

Presentation materials

There are no materials yet.