Institute of Mathematics

Talk

Modul:   MAT075  Zurich Graduate Colloquium

What is... a branching process?

Benedetta Cavalli talk

Date: 04.12.18  Time: 17.15 - 18.30  Room:

During the Victorian age, several aristocratic english families started to fear that their family names could become extinct. Was there something real behind that concern or was it just unfounded paranoia? In 1873 Sir Francis Galton asked the following question in an issue of the Educational Times: "How many male children (on average) must each generation of a family have in order for the family name to continue in perpetuity? Soon after, Reverend Henry William Watson replied with a solution and in 1874 the two wrote a joint paper entitled "On the probability of extinction of families". This marks the beginning of the study of what are today called branching processes: powerful probabilistic tools for exploiting branching structures naturally arising not only in population dynamics but also in many other fields. The aim of this lecture is to give an introduction to the topic and, of course, a precise answer to Galton’s question.