On band modules and $\tau$-tilting finiteness

Abstract

In this paper, motivated by a $\tau$-tilting version of the Brauer-Thrall Conjectures, we study general properties of band modules and their endomorphisms in the module category of a finite dimensional algebra. As an application we describe properties of torsion classes containing band modules. Furthermore, we show that a special biserial algebra is $\tau$-tilting finite if and only if no band module is a brick. We also recover a criterion for the $\tau$-tilting finiteness of Brauer graph algebras in terms of the Brauer graph.

To appear in Mathematische Zeitschrift. Substantial re-write: introduced tau-tilting version of the Brauer-Thrall conjectures for finite dimensional algebras and proof of the conjectures for special biserial algebras; removed Proposition 3.1 which contained a mistake; new proof of the criterion of tau-tilting finiteness for special biserial algebras