On higher torsion classes

Abstract

Building on the embedding of an $n$-abelian category $\mathcal{M}$ into an abelian category $\mathcal{A}$ as an $n$-cluster-tilting subcategory of $\mathcal{A}$, in this paper we relate the $n$-torsion classes of $\mathcal{M}$ with the torsion classes of $\mathcal{A}$. Indeed, we show that every $n$-torsion class in $\mathcal{M}$ is given by the intersection of a torsion class in $\mathcal{A}$ with $\mathcal{M}$. Moreover, we show that every chain of $n$-torsion classes in the $n$-abelian category $\mathcal{M}$ induces a Harder-Narasimhan filtration for every object of $\mathcal{M}$. We use the relation between $\mathcal{M}$ and $\mathcal{A}$ to show that every Harder-Narasimhan filtration induced by a chain of $n$-torsion classes in $\mathcal{M}$ can be induced by a chain of torsion classes in $\mathcal{A}$. Furthermore, we show that $n$-torsion classes are preserved by Galois covering functors, thus we provide a way to systematically construct new (chains of) $n$-torsion classes.

Published in \emph{Nagoya Journal of Mathematics}

References in corpus (2)

• Higher Auslander's formula
• The symplectic geometry of higher Auslander algebras: Symmetric products of disks

Cited by in corpus (1)

• A characterisation of higher torsion classes