2014/06/06 by Sorensen, Claus
#FOS: Mathematics #Number Theory (math.NT)
paper · doi:10.48550/arxiv.1406.1830
The goal of this paper is to reformulate the conjectural "Ihara lemma" for U(n) in terms of the local Langlands correspondence in families πΣ(⋅), as currently being developed by Emerton and Helm. The reformulation roughly takes the following form. Suppose we are given an irreducible mod ℓ Galois representation r, which is modular of full level (and small weight), and a finite set of places Σ -- none of which divide ℓ. Then πΣ(r) exists, and has a global realization as a natural module of algebraic modular forms, where r is the universal Σ-deformation of r. This is unconditional for n=2, where Ihara's lemma is an almost trivial consequence of the strong approximation theorem.