Title: Flat groups and graphs
Speaker: Jacqui Ramagge (University of Wollongong)
Abstract: In 1994 George Willis defined a scale function for a totally disconnected locally compact group $G$ and the notion of a tidy subgroup for an element $x\in G$. In 2002 Rögnvaldur Möller gave a graphical characterisation of tidy subgroups for fixed $x\in G$. The aim of this talk is to give an overview of joint work with Cheryl Praeger and George Willis generalising this result to certain semigroups of elements in $G$. No previous knowledge of the structure theory for locally compact totally disconnected groups will be assumed; the talk should be accessible to students.