The free product structure of diffeomorphism groups

by Prof. Thomas Koberda (University of Virginia, USA)

Thursday 10 Aug 2017, 16:00 → 17:00 Asia/Kolkata

AG-69 (TIFR, Mumbai)

Abstract: I will discuss some aspects of the algebraic structure of finitely generated groups of diffeomorphisms of compact one-manifolds. In articular, we show that if $G$ is not virtually metabelian then (G \times Z)*Z cannot act faithfully by C^2 diffeomorphisms on a compact one-manifold. Among the consequences of this result is a completion of the classification of right-angled Artin groups which admit faithful C^{\infty} actions on the circle, a program initiated together with H. Baik and S. Kim. This represents joint work with S. Kim.