Locally analytic vector bundles on the Fargues–Fontaine curve

Abstract

We develop a version of Sen theory for equivariant vector bundles on the Fargues–Fontaine curve. We show that every equivariant vector bundle canonically descends to a locally analytic vector bundle. A comparison with the theory of $(\phi ,\Gamma )$-modules in the cyclotomic case then recovers the Cherbonnier–Colmez decompletion theorem. Next, we focus on the subcategory of de Rham locally analytic vector bundles. Using the $p$-adic monodromy theorem, we show that each locally analytic vector bundle $\mathcal{ℰ}$ has a canonical differential equation for which the space of solutions has full rank. As a consequence, $\mathcal{ℰ}$ and its sheaf of solutions $\mathrm{Sol}<!--FUNCTION\; APPLICATION-->(\mathcal{ℰ})$ are in a natural correspondence, which gives a geometric interpretation of a result of Berger on $(\phi ,\Gamma )$-modules. In particular, if $V$ is a de Rham Galois representation, its associated filtered $(\phi ,N,G_K)$-module is realized as the space of global solutions to the differential equation. A key to our approach is a vanishing result for the higher locally analytic vectors of representations satisfying the Tate–Sen formalism, which is also of independent interest.