Quantized Vershik-Kerov Theory and Quantized Central Measures on Branching Graphs

TL;DR

This paper develops a quantized character theory for inductive systems of compact quantum groups, especially quantum unitary groups, using KMS states, and establishes a Vershik-Kerov approximation theorem for extremal quantized characters.

Contribution

It introduces a novel quantized character theory for quantum groups based on KMS states and provides a Vershik-Kerov type approximation theorem for extremal cases.

Findings

Quantized trace interpreted as a quantized character linked to KMS states.

Established a Vershik-Kerov approximation theorem for extremal quantized characters.

Compared the new theory with Gorin's q-Gelfand-Tsetlin graph approach.

Abstract

We propose a natural quantized character theory for inductive systems of compact quantum groups based on KMS states on AF-algebras following Stratila-Voiculescu's work (Stratila-Voiculescu, 1975) (or (Enomoto-Izumi, 2016)), and give its serious investigation when the system consists of quantum unitary groups $U_q(N)$ with $q$ in $(0,1)$. The key features of this work are: The "quantized trace" of a unitary representation of a compact quantum group can be understood as a quantized character associated with the unitary representation and its normalized one is captured as a KMS state with respect to a certain one-parameter automorphism group related to the so-called scaling group. In this paper we provide a Vershik-Kerov type approximation theorem for extremal quantized characters (called the ergodic method) and also compare our quantized character theory for the inductive system of $U_q(N)$ with Gorin's theory on $q$-Gelfand-Tsetlin graphs (Gorin, 2012).