School of Mathematics, Statistics and Physics

Seminar Item

Pure Maths (Algebra and Geometry) - Ana Khukhro (Cambridge)

A new characterisation of virtually free groups

Date/Time: Monday 16 November, 1.30pm - Algebra and Geometry Seminar

Venue: Zoom


A finite graph that can be obtained from a given graph by contracting edges and removing vertices and edges is said to be a minor of this graph. Minors have played an important role in graph theory, ever since the well-known result of Kuratowski that characterised planar graphs as those that do not admit the complete graph on 5 vertices nor the complete bipartite graph on (3,3) vertices as minors. In this talk, we will explore how this concept interacts with some notions from geometric group theory, and describe a new characterisation of virtually free groups in terms of minors of their Cayley graphs.