Arithmetic and Geometric Langlands Program
Xinwen Zhu
TL;DR
This survey explains how geometric Langlands ideas, notably the geometric Satake equivalence and global-local categorical correspondences, illuminate classical arithmetic Langlands and arithmetic geometry problems. It outlines a 2-categorical framework linking local and global Langlands parameters to categories of sheaves and automorphic data via the $L$-group ${}^L G$ (and the enhanced group ${}^cG$), excursion operators, and spectral actions. It highlights arithmetic applications to Shimura varieties, local models, congruence relations, generic Tate cycles, and the Beilinson–Bloch–Kato conjecture for Rankin–Selberg motives, including recent function-field results. The work synthesizes function-field proofs (e.g., Lafforgue) with conjectural, category-based formulations aimed at number fields, guided by geometric and physical insights.
Abstract
We explain how the geometric Langlands program inspires some recent new prospectives of classical arithmetic Langlands program and leads to the solutions of some problems in arithmetic geometry.
