The tempered disk and the tempered cohomology
Federico Bambozzi, Bruno Chiarellotto, Pietro Vanni
TL;DR
The paper develops a tempered, derived-analytic framework for non-archimedean geometry by associating a spectrum $\mathfrak{S}(A)$ to ind-Banach rings and introducing tempered tubes and tempered power series. It defines tempered convergent cohomology $H^{\bullet}_{\mathrm{temp}}(X)$ via the Hodge-completed derived de Rham complex on tempered tubes and proves independence from choices, with a crystalline-cohomology comparison for smooth proper $X$. A key innovation is the reinterpretation of log-growth transfer theorems for $p$-adic differential equations as continuity statements within the derived analytic spectrum, using tempered open subsets of the affine line. The work also develops a robust infrastructure—quasi-abelian categories, Ind-Banach modules, bornological models, derived analytic stacks, and an analytic cotangent complex—to underpin tempered cohomology and its geometric and cohomological applications in non-archimedean settings.
Abstract
Consider a non-archimedean valuation ring V (K its fraction field, in mixed characteristic): inspired by some views presented by Scholze, we introduce a new point of view on the non-archimedean analytic setting in terms of derived analytic geometry (then associating a "spectrum" to each ind-Banach algebra). We want to look at the behaviour of this spectrum from a differential point of view. In such a spectrum, for example, there exist open subsets having functions with log-growth as sections for the structural sheaf. In this framework, a transfer theorem for the log-growth of solutions of p-adic differential equations can be interpreted as a continuity theorem (analogue to the transfer theorem for their radii of convergence in the Berkovich spaces). As a dividend of such a theory, we define a new cohomology theory in terms of the Hodge-completed derived de Rham cohomology of the ind-Banach derived analytic space associated to a smooth k-scheme, X_k (k residual field of V), via the use of "tempered tubes". We finally compare our tempered de Rham cohomology with crystalline cohomology.
