Mutations of reflections and existence of pseudo-acyclic orderings for type $A_n$

TL;DR

This paper proves a conjecture about the existence of special orderings of vertices in type A_n quivers that ensure consistent reflection representations across mutation sequences, using decomposition into elementary swaps.

Contribution

It establishes the existence of pseudo-acyclic orderings for type A_n quivers, confirming a conjecture through decomposition and relation checking.

Findings

Confirmed the conjecture for all type A_n quivers.

Decomposed mutation sequences into elementary swaps.

Validated relations by Barot and Marsh.

Abstract

In a recent paper by K.-H. Lee, K. Lee and M. Mills, a mutation of reflections in the universal Coxeter group is defined in association with a mutation of a quiver. A matrix representation of these reflections is determined by a linear ordering on the set of vertices of the quiver. It was conjectured that there exists an ordering (called a pseudo-acyclic ordering in this paper) such that whenever two mutation sequences of a quiver lead to the same labeled seed, the representations of the associated reflections also coincide. In this paper, we prove this conjecture for every quiver mutation-equivalent to an orientation of a type $A_n$ Dynkin diagram by decomposing a mutation sequence into a product of elementary swaps and checking relations studied by Barot and Marsh.