English

p-adic Tate conjectures and abeloid varieties

Algebraic Geometry 2019-11-26 v2 Number Theory

Abstract

We explore Tate-type conjectures over pp-adic fields. We study a conjecture of Raskind that predicts the surjectivity of (NS(XKˉ)ZQp)GKHet2(XKˉ,Qp(1))GK ({\rm NS}(X_{\bar{K}}) \otimes_{\mathbb{Z}}\mathbb{Q}_p)^{G_K} \longrightarrow H^2_{\rm et}(X_{\bar{K}},\mathbb{Q}_p(1))^{G_K} if XX is smooth and projective over a pp-adic field KK and has totally degenerate reduction. Sometimes, this is related to pp-adic uniformisation. For abelian varieties, Raskind's conjecture is equivalent to the question whether Hom(A,B)QpHomGK(Vp(A),Vp(B)) {\rm Hom}(A,B)\otimes{\mathbb{Q}}_p \,\to\, {\rm Hom}_{G_K}(V_p(A),V_p(B)) is surjective if AA and BB are abeloid varieties over KK. Using pp-adic Hodge theory and Fontaine's functors, we reformulate both problems into questions about the interplay of Q\mathbb{Q}- versus Qp\mathbb{Q}_p-structures inside filtered (φ,N)(\varphi,N)-modules. Finally, we disprove all of these conjectures and questions by showing that they can fail for algebraisable abeloid surfaces.

Keywords

Cite

@article{arxiv.1903.05630,
  title  = {p-adic Tate conjectures and abeloid varieties},
  author = {Oliver Gregory and Christian Liedtke},
  journal= {arXiv preprint arXiv:1903.05630},
  year   = {2019}
}

Comments

44 pages, final version

R2 v1 2026-06-23T08:07:16.395Z