Pure Postgraduate Seminar - R-Trees, by Vlad Vankov, Southampton Seminar

Event details

Find out what R-trees are! We shall see some similarities to Bass-Serre theory of trees, however we'll get R-trees arising in interesting situations, specifically as limits of sequences of negatively curves spaces. As an application, we will discuss a result of Paulin, which claims that a torsion-free hyperbolic group G has infinite outer automorphism group if and only if G splits over a cyclic subgroup.