Generating series and matrix models for meandric systems with one shallow side

TL;DR

This paper explores a special class of meandric systems with one shallow side, providing generating series formulas and proposing random matrix models linked to quantum information theory.

Contribution

It introduces explicit formulas for generating series of meandric systems with one shallow side and proposes quantum-inspired random matrix models.

Findings

Formulas for generating series of meandric systems with one shallow side

Explicit enumeration of irreducible objects in these systems

Random matrix models connected to quantum channels

Abstract

In this article, we investigate meandric systems having one shallow side: the arch configuration on that side has depth at most two. This class of meandric systems was introduced and extensively examined by I. P. Goulden, A. Nica, and D. Puder in 2020. Shallow arch configurations are in bijection with the set of interval partitions. We study meandric systems by using moment-cumulant transforms for non-crossing and interval partitions, corresponding to the notions of free and boolean independence, respectively, in non-commutative probability. We obtain formulas for the generating series of different classes of meandric systems with one shallow side, by explicitly enumerating the simpler, irreducible objects. In addition, we propose random matrix models for the corresponding meandric polynomials, which can be described in the language of quantum information theory, in particular that of quantum channels.