English

Moduli of $G$-bundles on rigid gerbes over affine curves

Number Theory 2026-02-24 v1 Algebraic Geometry Representation Theory

Abstract

We geometrize the basic cohomology set H1(KalF,G)basicH^{1}(\text{Kal}_{F}, G)_{\text{basic}} for a global function field FF. We do this by constructing a v-stack BunG,Fe\text{Bun}_{G,F}^{e} which has localization maps to Fargues' analogous stack BunG,Fve\text{Bun}_{G,F_{v}}^{e} for all places vv of FF and whose semistable locus is the disjoint union of BunGb,F\text{Bun}_{G_{b},F} for all bH1(KottF×FKalF,G)basicb \in H^{1}(\text{Kott}_{F} \times_{F} \text{Kal}_{F},G)_{\text{basic}}. We also prove a version of Tate-Nakayama duality for H1(KottF×FKalF,G)basicH^{1}(\text{Kott}_{F} \times_{F} \text{Kal}_{F},G)_{\text{basic}}, which lets us state a conjectural multiplicity formula for discrete automorphic representations of G(AF)G(\mathbb{A}_{F}) adapted to this new cohomology set.

Keywords

Cite

@article{arxiv.2602.19382,
  title  = {Moduli of $G$-bundles on rigid gerbes over affine curves},
  author = {Peter Dillery},
  journal= {arXiv preprint arXiv:2602.19382},
  year   = {2026}
}

Comments

35 pages; comments welcome!