Semi-Bousfield classes and nonmonotone perversities
Abstract
In the generality of a rigidly-compactly generated tensor triangulated category, we introduce semi-Bousfield classes in terms of the vanishing of the tensor product in positive degrees with respect to a fixed reasonable -structure. We show that semi-Bousfield classes provide a common generalisation of Bousfield classes and compactly generated tensor-compatible -structures. Then we specialise to the setting of the unbounded derived category of a Noetherian scheme and show that the stratification bijection naturally extends to an assignment which takes a (not necessarily monotone) perversity on to a semi-Bousfield class in . If is regular, this assignment constitutes a stratification of the whole semi-Bousfield lattice, while in the singular case, its image consists precisely of those semi-Bousfield classes arising from objects of finite Tor-dimension. Restricting this bijection to monotone perversities recovers the recent classification of compactly generated tensor-compatible -structures of Dubey and Sahoo, (arXiv:2204.05015).
Comments: 43 pages, comments are welcome
Cite
@article{arxiv.2605.30262,
title = {Semi-Bousfield classes and nonmonotone perversities},
author = {Dolors Herbera and Michal Hrbek and Giovanna Le Gros},
journal= {arXiv preprint arXiv:2605.30262},
year = {2026}
}