Cayley graph expanders, pro-p-groups and buildings
Alina Vdovina (U Newcastle)
Wednesday 17th February, 2010 16:00-17:00 204
We present new infinite families of expander graphs of vertex degree 4, which is the minimal possible degree for Cayley graph expanders. Our families define a tower of coverings and are given as Cayley graphs of finite 2-groups with very short presentations (two generators and four relations).