English

A finer Tate duality theorem for local Galois symbols

Number Theory 2018-05-07 v2

Abstract

Let KK be a finite extension of Qp\mathbb{Q}_p. Let AA, BB be abelian varieties over KK of good reduction. For any integer m1m\geq 1, we consider the Galois symbol K(K;A,B)/mH2(K,A[m]B[m])K(K;A,B)/m\rightarrow H^2(K,A[m]\otimes B[m]), where K(K;A,B)K(K;A,B) is the Somekawa KK-group attached to A,BA,B. This map is a generalization of the Galois symbol K2M(K)/mH2(K,μm2)K_2^M(K)/m\rightarrow H^2(K,\mu_m^{\otimes 2}) of the Bloch-Kato conjecture, where K2M(K)K_2^M(K) is the Milnor KK-group of KK. In this paper we give a geometric description of the image of this generalized Galois symbol by looking at the Tate duality pairing H2(K,A[m]B[m])×HomGK(A[m],B[m])Z/m,H^{2}(K,A[m]\otimes B[m])\times\mathrm{Hom}_{G_{K}}(A[m],B^{\star}[m])\rightarrow\mathbb{Z}/m, where BB^\star is the dual abelian variety of BB. Under this perfect pairing we compute the exact annihilator of the image of the Galois symbol in terms of an object of integral pp-adic Hodge theory.

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Cite

@article{arxiv.1703.06974,
  title  = {A finer Tate duality theorem for local Galois symbols},
  author = {Evangelia Gazaki},
  journal= {arXiv preprint arXiv:1703.06974},
  year   = {2018}
}

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32 pages