Automating the stable rank computation for special biserial algebras

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Srivastava, Suyash, Kuber, Amit
Format: Preprint
Publié: 2024
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866914856019427328
author Srivastava, Suyash
Kuber, Amit
author_facet Srivastava, Suyash
Kuber, Amit
contents Given a special biserial algebra $Λ$ over an algebraically closed field, let $\mathrm{rad}_Λ$ denote the radical of its module category. The authors showed with Sinha that the stable rank of a special biserial algebra $Λ$, i.e., the least ordinal $γ$ satisfying $\mathrm{rad}_Λ^γ=\mathrm{rad}_Λ^{γ+1}$, is strictly bounded above by $ω^2$. We use finite automata to give simple algorithmic proofs, complete with their time complexity analyses, of two key ingredients in the proof of this result--the first one states that certain linear orders called hammocks associated with such algebras are \emph{finite description linear orders}, i.e., they lie in the smallest class of linear orders that contains finite linear orders and $ω$, and that is closed under isomorphisms, order-reversals, binary sums, co-lexicographic products and finitary shuffles. We also document a complete proof of the result that the class of order types(=order-isomorphism classes) of finite description linear orders coincides with that of languages of finite automata under inorder.
format Preprint
id arxiv_https___arxiv_org_abs_2407_02326
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Automating the stable rank computation for special biserial algebras
Srivastava, Suyash
Kuber, Amit
Representation Theory
16S90, 68Q45, 06A05, 16G20
Given a special biserial algebra $Λ$ over an algebraically closed field, let $\mathrm{rad}_Λ$ denote the radical of its module category. The authors showed with Sinha that the stable rank of a special biserial algebra $Λ$, i.e., the least ordinal $γ$ satisfying $\mathrm{rad}_Λ^γ=\mathrm{rad}_Λ^{γ+1}$, is strictly bounded above by $ω^2$. We use finite automata to give simple algorithmic proofs, complete with their time complexity analyses, of two key ingredients in the proof of this result--the first one states that certain linear orders called hammocks associated with such algebras are \emph{finite description linear orders}, i.e., they lie in the smallest class of linear orders that contains finite linear orders and $ω$, and that is closed under isomorphisms, order-reversals, binary sums, co-lexicographic products and finitary shuffles. We also document a complete proof of the result that the class of order types(=order-isomorphism classes) of finite description linear orders coincides with that of languages of finite automata under inorder.
title Automating the stable rank computation for special biserial algebras
topic Representation Theory
16S90, 68Q45, 06A05, 16G20
url https://arxiv.org/abs/2407.02326