Line bundles on rigid spaces in the -topology
arXiv:2012.07918
Abstract
For a smooth rigid space over a perfectoid field extension of , we investigate how the -Picard group of the associated diamond differs from the analytic Picard group of . To this end, we construct a left-exact "Hodge--Tate logarithm" sequence \[0\to \mathrm{Pic}_{\mathrm{an}}(X)\to \mathrm{Pic}_v(X^\diamondsuit)\to H^0(X,Ω_X^1)\{-1\}.\] We deduce some analyticity criteria which have applications to -adic modular forms. For algebraically closed , we show that the sequence is also right-exact if is proper or one-dimensional. In contrast, we show that for the affine space , the image of the Hodge--Tate logarithm consists precisely of the closed differentials. It follows that up to a splitting, -line bundles may be interpreted as Higgs bundles. For proper , we use this to construct the -adic Simpson correspondence of rank one.
added section on analyticity criteria, generalised setting to any perfectoid base field