Comptes Rendus. Mathématique (Jan 2023)

The size of a stratifying system can be arbitrarily large

  • Treffinger, Hipolito

DOI
https://doi.org/10.5802/crmath.385
Journal volume & issue
Vol. 361, no. G1
pp. 15 – 19

Abstract

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In this short note we construct two families of examples of large stratifying systems in module categories of algebras. The first examples consist on stratifying systems of infinite size in the module category of an algebra $A$. In the second family of examples we show that the size of a finite stratifying system in the module category of a finite dimensional algebra $A$ can be arbitrarily large in comparison to the number of isomorphism classes of simple $A$-modules. We note that both families of examples are built using well-established results in higher homological algebra.