School of Mathematics & Physics, University of Lincoln
On Wednesday the 26th of February 2020, Dr Daniel Woodhouse (University of Oxford) visited the Charlotte Scott Centre for Algebra and gave a talk “Leighton’s graph covering theorem”.
Abstract: Leighton’s theorem for graphs states that any pair of finite graphs with common universal covers have a common finite cover. Equivalently, this says that any pair of uniform lattices in the automorphism groups of a tree can be commensurated. I will discuss the significance of this theorem, recent generalizations, and how it can be applied in geometric group theory.