Article contents
EXTENSIONS OF VECTOR BUNDLES ON THE FARGUES-FONTAINE CURVE
Published online by Cambridge University Press: 14 May 2020
Abstract
We completely classify the possible extensions between semistable vector bundles on the Fargues–Fontaine curve (over an algebraically closed perfectoid field), in terms of a simple condition on Harder–Narasimhan (HN) polygons. Our arguments rely on a careful study of various moduli spaces of bundle maps, which we define and analyze using Scholze’s language of diamonds. This analysis reduces our main results to a somewhat involved combinatorial problem, which we then solve via a reinterpretation in terms of the Euclidean geometry of HN polygons.
MSC classification
- Type
- Research Article
- Information
- Journal of the Institute of Mathematics of Jussieu , Volume 21 , Issue 2 , March 2022 , pp. 487 - 532
- Copyright
- © The Author(s) 2020. Published by Cambridge University Press
Footnotes
DH is grateful to Christian Johansson for some useful conversations about the material in § 3.2, and Peter Scholze for providing early access to the manuscript [13] and for some helpful conversations about the results therein. The project group students (CB, TF, SH, QL, AW, and LY) thank DH and Kiran Kedlaya for suggesting the problem. TF gratefully acknowledges the support of an NSF Graduate Fellowship. LY gratefully acknowledges the support of the National Defense Science and Engineering Graduate Fellowship. We would also like to thank David Linus Hamann and the referee for their valuable feedback on the first version of this paper.
References
- 6
- Cited by