English

On the spectrum and support theory of a finite tensor category

Category Theory 2023-12-01 v4 Quantum Algebra Rings and Algebras Representation Theory

Abstract

Finite tensor categories (FTCs) T\bf T are important generalizations of the categories of finite dimensional modules of finite dimensional Hopf algebras, which play a key role in many areas of mathematics and mathematical physics. There are two fundamentally different support theories for them: a cohomological one and a universal one based on the noncommutative Balmer spectra of their stable (triangulated) categories T\underline{\bf T}. In this paper we introduce the key notion of the categorical center CTC^\bullet_{\underline{\bf T}} of the cohomology ring RTR^\bullet_{\underline{\bf T}} of an FTC, T\bf T. This enables us to put forward a complete and detailed program for determining the exact relationship between the two support theories, based on CTC^\bullet_{\underline{\bf T}} of the cohomology ring RTR^\bullet_{\underline{\bf T}} of an FTC, T\bf T. More specifically, we construct a continuous map from the noncommutative Balmer spectrum of an FTC, T\bf T, to the Proj\text{Proj} of the categorical center CTC^\bullet_{\underline{\bf T}}, and prove that this map is surjective under a weaker finite generation assumption for T\bf T than the one conjectured by Etingof-Ostrik. Under stronger assumptions, we prove that (i) the map is homeomorphism and (ii) the two-sided thick ideals of T\underline{\bf T} are classified by the specialization closed subsets of ProjCT\text{Proj} C^\bullet_{\underline{\bf T}}. We conjecture that both results hold for all FTCs. Many examples are presented that demonstrate how in important cases CTC^\bullet_{\underline{\bf T}} arises as a fixed point subring of RTR^\bullet_{\underline{\bf T}} and how the two-sided thick ideals of T\underline{\bf T} are determined in a uniform fashion. The majority of our results are proved in the greater generality of monoidal triangulated categories.

Keywords

Cite

@article{arxiv.2112.11170,
  title  = {On the spectrum and support theory of a finite tensor category},
  author = {Daniel K. Nakano and Kent B. Vashaw and Milen T. Yakimov},
  journal= {arXiv preprint arXiv:2112.11170},
  year   = {2023}
}

Comments

Appendix B has been revised from the prior version after considering comments from Greg Stevenson