English

p-adic level raising on the eigenvariety for U(3)

Number Theory 2025-04-02 v1 Representation Theory

Abstract

We prove level raising results for pp-adic automorphic forms on definite unitary groups U(3)/QU(3)/\mathbb{Q} and deduce some intersection points on the eigenvariety. Let ll be an inert prime where the level subgroups varies, if there is a non-very-Eisenstein point ϕ\phi on the old component (generically parametrizing forms old at ll) satisfying Tl(ϕ)=l(l3+1)T_{l}(\phi)=l(l^3+1), then this point also lies in the new component (generically parametrizing forms new at ll). This provides a pp-adic analogue of Bella\"iche and Graftieaux's mod pp level raising for classical automorphic forms on U(3)U(3), and also generalizes James Newton's pp-adic level raising results for definite quaternion algebras. Key ingredients include abelian Ihara lemma (proved for any definite unitary group U(n)U(n)) and some duality arguments about certain Hecke modules. Finally we also discuss some methods to construct such points explicitly and further development.

Keywords

Cite

@article{arxiv.2504.00821,
  title  = {p-adic level raising on the eigenvariety for U(3)},
  author = {Ruishen Zhao},
  journal= {arXiv preprint arXiv:2504.00821},
  year   = {2025}
}

Comments

28 pages. Comments are welcome!

R2 v1 2026-06-28T22:42:27.643Z