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Monobrick, a uniform approach to torsion-free classes and wide subcategories.
- Source :
-
Advances in Mathematics . Dec2021, Vol. 393, pN.PAG-N.PAG. 1p. - Publication Year :
- 2021
-
Abstract
- For a length abelian category, we show that all torsion-free classes can be classified by using only the information on bricks, including non functorially-finite ones. The idea is to consider the set of simple objects in a torsion-free class, which has the following property: it is a set of bricks where every non-zero map between them is an injection. We call such a set a monobrick. In this paper, we provide a uniform method to study torsion-free classes and wide subcategories via monobricks. We show that monobricks are in bijection with left Schur subcategories, which contains all subcategories closed under extensions, kernels and images, thus unifies torsion-free classes and wide subcategories. Then we show that torsion-free classes bijectively correspond to cofinally closed monobricks. Using monobricks, we deduce several known results on torsion(-free) classes and wide subcategories (e.g. finiteness result and bijections) in length abelian categories, without using τ -tilting theory. For Nakayama algebras, left Schur subcategories are the same as subcategories closed under extensions, kernels and images, and we show that its number is related to the large Schröder number. [ABSTRACT FROM AUTHOR]
- Subjects :
- *ABELIAN categories
*BIJECTIONS
*BRICKS
*ALGEBRA
*ABELIAN groups
*FINITE, The
Subjects
Details
- Language :
- English
- ISSN :
- 00018708
- Volume :
- 393
- Database :
- Academic Search Index
- Journal :
- Advances in Mathematics
- Publication Type :
- Academic Journal
- Accession number :
- 153783722
- Full Text :
- https://doi.org/10.1016/j.aim.2021.108113