Dévissage for Algebraic K-theory of Small Stable $\infty$-categories
Chunhui Wei
TL;DR
This work extends Quillen's dévissage to small stable $\infty$-categories by introducing dévissage and fillability conditions for a stable pair $(\mathcal{C},\mathcal{A})$, and shows that the inclusion $\mathcal{A}\hookrightarrow\mathcal{C}$ induces isomorphisms on higher $K$-groups $K_n$ for $n\ge 1$ under a weak dévissage condition and on $K_0$ under strong dévissage. It develops a framework of Gap and Gap^w constructions to categorify fibers and loops, enabling a robust additivity and fiber/loop calculus for universal localizing invariants, including $K$-theory. Higher and stronger notions of fillability yield vanishing results for quotients $\mathrm{Q}(\mathcal{C},\mathcal{A})$ and, in many cases, force $K$-groups of the larger category to vanish or coincide with those of the subcategory, providing structural constraints on stable $\infty$-categories. The paper also connects these dévissage techniques with classical quasi-abelian and abelian settings, offering a new proof pathway for Quillen's theorem through derived categories and functor categories, and highlighting the versatility of the $\infty$-categorical approach in higher algebraic $K$-theory.
Abstract
In this article, we extend Quillen's Dévissage Theorem to small stable $\infty$-categories. To be precise, we establish sufficient conditions under which the non-negative $K$-groups of a small stable $\infty$-category coincide with those of a stable subcategory thereof.
