Approximation properties of torsion classes
Abstract We strengthen a result of Bagaria and Magidor ( Trans. Amer. Math. Soc . 366 (2014), no. 4, 1857–1877) about the relationship between large cardinals and torsion classes of abelian groups, and prove that the Maximum Deconstructibility principle introduced in Cox ( J. Pure Appl. Algebra 226 (2022), no. 5) requires large cardinals; it sits, implication‐wise, between Vopěnka's Principle and the existence of an ‐strongly compact cardinal. While deconstructibility of a class of modules always implies the precovering property by Saorín and Šťovíček ( Adv. Math . 228 (2011), no. 2, 968–1007), the concepts are (consistently) nonequivalent, even for classes of abelian groups closed under extensions, homomorphic images, and colimits.
Authors
- Sean Cox (ORCID: https://orcid.org/0000-0001-5546-7079)
- Jan Trlifaj (ORCID: https://orcid.org/0000-0001-5773-8661)
- Alejandro Poveda
Institutions
- Harvard University (US)
- Virginia Commonwealth University (US)
- Charles University (CZ)
- Mathematical Sciences Research Institute (US)
Publication Details
- Journal
- Bulletin of the London Mathematical Society
- Published
- 2024-10-16
- DOI
- https://doi.org/10.1112/blms.13169
- Citations
- 1
- Primary Topic
- Rings, Modules, and Algebras
- Type
- article
- Field-Weighted Citation Impact
- 1.27
Funders
- National Science Foundation
- Grantová Agentura České Republiky