Limits of characters of wreath products ${\mathfrak S}_{n}(T)$ of a compact group $T$ with the symmetric groups and characters of ${\mathfrak S}_{\infty}(T)$, I

Abstract

In the first half of this paper, all the limits of irreducible characters of $G_{n} = {\mathfrak S}_{n}(T)$ as $n \to \infty$ are calculated. The set of all \emph{continuous} limit functions on $G = {\mathfrak S}_{\infty}(T)$ is exactly equal to the set of all characters of $G$ determined in [HH6]. We give a necessary and sufficient condition for a series of irreducible characters of $G_{n}$ to have a continuous limit and also such a condition to have a discontinuous limit. In the second half, we study the limits of characters of certain induced representations of $G_{n}$ which are usually reducible. The limits turn out to be characters of $G$, and we analyse which of irreducible components are responsible to these limits.