English

On $\mathsf{G}$-isoshtukas over function fields

Algebraic Geometry 2021-06-17 v3 Number Theory

Abstract

In this paper we classify isogeny classes of global G\mathsf{G}-shtukas over a smooth projective curve C/FqC/\mathbb{F}_q (or equivalently σ\sigma-conjugacy classes in G(FFqFq)\mathsf{G}(\mathsf{F} \otimes_{\mathbb{F}_q} \overline{\mathbb{F}_q}) where F\mathsf{F} is the field of rational functions of CC) by two invariants κˉ,νˉ\bar\kappa,\bar\nu extending previous works of Kottwitz. This result can be applied to study points of moduli spaces of G\mathsf{G}-shtukas and thus is helpful to calculate their cohomology.

Cite

@article{arxiv.2003.07389,
  title  = {On $\mathsf{G}$-isoshtukas over function fields},
  author = {Paul Hamacher and Wansu Kim},
  journal= {arXiv preprint arXiv:2003.07389},
  year   = {2021}
}

Comments

26 pages, v3: Added a short exposition of related works in the introduction; elaborated on the localisation map of $\sigma$-conjugacy classes and fixed a minor mistake in the formula of Newton point of the localisation of a $\sigma$-conjugacy class

R2 v1 2026-06-23T14:16:37.171Z