SEMINAR: Groups and Combinatorics Seminar: Mariagrazia Bianchi, 4pm Feb 12

Speaker: Mariagrazia Bianchi (Università degli Studi di Milano)

Title: Conjugacy class sizes in finite groups: variations on the theme

Time and place: 4pm Tuesday 12 Feb 2019, Weatherburn LT

Abstract: The study of conjugacy class sizes goes back to the beginning of the last century with Burnside's result, Miller's studies on groups with few conjugacy classes and Ito who began the study of the structure of a group in terms of the number of conjugacy classes. Over the last 30 years the subject has become fashionable and many papers have been written on this topic. In this talk I try to summarize some results obtained by using two particular graphs: the common divisor graph and the prime graph in relationship with conjugacy class sizes and finally the variation regarding the so-called vanishing classes, that are those classes of elements g for which there exists an irreducible non linear character chi such that chi(g)=0.