English

The importance of being isolated

Commutative Algebra 2026-05-20 v1 Category Theory

Abstract

We give both a sufficient condition for and an obstruction to the derived category of a commutative ring being generated by its residue fields. As an illustration, we exhibit a ring for which Foxby's small support classifies localizing subcategories despite the failure of the local-to-global principle. We also conclude that the residue fields do not generate for a polynomial ring in infinitely many variables. Finally, we give a necessary and sufficient criterion for the derived category to satisfy the local-to-global principle; it turns out to depend solely on the topology of the spectrum.

Keywords

Cite

@article{arxiv.2605.19617,
  title  = {The importance of being isolated},
  author = {Scott Balchin and Juan Omar Gómez and Greg Stevenson},
  journal= {arXiv preprint arXiv:2605.19617},
  year   = {2026}
}

Comments

8 pages, comments welcome