# Probability theory for random groups arising in number theory

### Melanie Matchett Wood

Department of Mathematics, Harvard University, Science Center Room 325, 1 Oxford Street, Cambridge, MA 02138, USA

This book chapter is published *open access.*

## Abstract

We consider the probability theory, and in particular the moment problem and universality theorems, for random groups of the sort that arise or are conjectured to arise in number theory, and in related situations in topology and combinatorics. The distributions of random groups that are discussed include those conjectured in the Cohen–Lenstra–Martinet heuristics to be the distributions of class groups of random number fields, as well as distributions of nonabelian generalizations, and those conjectured to be the distributions of Selmer groups of random elliptic curves. For these sorts of distributions on finite and profinite groups, we survey what is known about the moment problem and universality, give a few new results including new applications, and suggest open problems.