The $k$-Plancherel measure and a Finite Markov Chain

TL;DR

This paper explores a growth process on $k$-bounded partitions related to $k$-Schur functions, revealing a finite Markov chain structure that governs its limiting behavior and conjecturing convergence to known limit shapes.

Contribution

It introduces a new growth process on $k$-cores with a stationary distribution called the $k$-Plancherel measure, connecting it to finite Markov chains and conjecturing its asymptotic shape.

Findings

The process's limit behavior is governed by a finite Markov chain with $k!$ states.

Conjecture that for fixed $k$, the process converges to a shape close to the uniform growth limit shape.

The Markov chain can be viewed as a TASEP over cyclic permutations of length $k+1$.

Abstract

Let $\mathcal{P}_k(n)$ denote the set of partitions of $n$ whose largest part is bounded by $k,$ which are in well-known bijection with $(k+1)$-cores $\mathcal{C}_k$. We study a growth process on $\mathcal{C}_k$, whose stationary distribution is the $k$-Plancherel measure, which is a natural extension of the Plancherel measure in the context of $k$-Schur functions. When $k\to\infty$ it converges to the Plancherel measure for partitions, a limit studied first by Vershik-Kerov. However, when $k$ is fixed and $n\to \infty$, we conjecture that it converges to a shape close to the limit shape from the uniform growth of partitions, as studied by Rost. We show that the limiting behavior, for fixed $k$, is governed by a finite Markov chain with $k!$ states over a subset of the $k$-bounded partitions or equivalently as a TASEP over cyclic permutations of length $k+1$. This paper initiates the study of these processes, state some theorems and several intriguing conjectures found by computations of the finite Markov chain.