Regular modules with preprojective Gabriel-Roiter submodules over $n$-Kronecker quivers

TL;DR

This paper investigates the structure of regular modules with preprojective Gabriel-Roiter submodules over wild n-Kronecker quivers, revealing infinite Gabriel-Roiter segments and detailed analysis for the case n=3 using Fibonacci numbers.

Contribution

It introduces a detailed study of Gabriel-Roiter measures for regular modules over n-Kronecker quivers, including the existence of infinitely many GR-segments and a characterization for n=3.

Findings

Existence of infinitely many Gabriel-Roiter segments.

Sequence of Gabriel-Roiter measures forms a chain of direct successors.

For n=3, measures are determined by dimension vectors in certain components.

Abstract

Let $Q$ be a wild $n$-Kronecker quiver, i.e., a quiver with two vertices, labeled by 1 and 2, and $n\geq 3$ arrows from 2 to 1. The indecomposable regular modules with preprojective Gabriel-Roiter submodules, in particular, those $\tau^{-i}X$ with $\udim X=(1,c)$ for $i\geq 0$ and some $1\leq c\leq n-1$ will be studied. It will be shown that for each $i\geq 0$ the irreducible monomorphisms starting with $\tau^{-i}X$ give rise to a sequence of Gabriel-Roiter inclusions, and moreover, the Gabriel-Roiter measures of those produce a sequence of direct successors. In particular, there are infinitely many GR-segments, i.e., a sequence of Gabriel-Roiter measures closed under direct successors and predecessors. The case $n=3$ will be studied in detail with the help of Fibonacci numbers. It will be proved that for a regular component containing some indecomposable module with dimension vector $(1,1)$ or $(1,2)$, the Gabriel-Roiter measures of the indecomposable modules are uniquely determined by their dimension vectors.