Denjoy homeomorphism of big surfaces.

In this talk we discuss homeomorphisms of big surfaces (big = infinitely generated fundamental group) coming from the classical Denjoy circle homeomorphism (which of course will be defined in the talk!). We show that mapping torii of these produce interesting fibrations of 3 manifolds such as the genus 2 handlebody.

This is joint work with Jesus Hernandez Hernandez (UNAM Morelia) and Chris Leininger (Rice University) (https://arxiv.org/abs/2508.02897)