The Layered Catalan Monoids: Structure and Determinants
M. H. Shahzamanian
TL;DR
The paper introduces Layered Catalan Monoids $LC_n$ and studies their semigroup-determinant properties within the $\ll$-smooth framework. It develops a canonical word-form for $LC_n$, proves $LC_n$ is $\ll$-smooth (singleton-rich and $\ll$-transitive), and applies the determinant analysis of Sha-Det2. The main result is that the semigroup determinant $\theta_{LC_n}(X)$ is non-zero precisely for $n \le 7$ and vanishes for $n \ge 8$, with explicit idempotent-decomposition reasoning. The findings illustrate a sharp threshold in determinant behavior for a natural Catalan-inspired monoid class and link to broader algebraic properties and potential coding-theoretic implications.
Abstract
In this paper, we introduce and study a class of monoids, called Layered Catalan Monoids (\( {LC}_n \)), which satisfy the structural conditions for $\ll$-smoothness as defined in~\cite{Sha-Det2}. These monoids are defined by specific identities inspired by Catalan monoids. We establish their canonical forms and compute their determinant, proving that it is non-zero for \(1 \leq n \leq 7\) but vanishes for \(n \geq 8\).
