English

Refining the Abel--Jacobi maps

Algebraic Geometry 2007-05-23 v1

Abstract

Given a smooth projective variety XX over a field kk of characteristic zero, we consider the composition of the de Rham cohomology cycle class map over kk from the Chow group CHq(X×kK)CH^q(X\times_kK), where KK is the field of fractions of henselization AhA^h of the local ring of a smooth closed point of a variety over the field kk with an appropriate projection: CHq(X×kK)p=1qgrFqpNqpHdR/k2qp(X)kΩAh/k,closedp,CH^q(X\times_kK)\longrightarrow\bigoplus_{p=1}^qgr_F^{q-p}N^{q-p} H^{2q-p}_{dR/k}(X)\otimes_k\Omega^p_{A^h/k,{\rm closed}}, where FF^{\bullet} and NN^{\bullet} are the Hodge and the coniveau filtrations on the de Rham cohomology, respectively. The classical Abel--Jacobi map corresponds to the composition of this homomorphism with the projection to the summand p=1p=1. This homomorphism is not injective, however, its composition with the embedding into the space p=1qgrFqpNqpHdR/k2qp(X)klimMd(ΩAM/kp1),\bigoplus_{p=1}^qgr_F^{q-p}N^{q-p}H^{2q-p}_{dR/k}(X)\otimes_k \lim_{\longleftarrow_M}d(\Omega^{p-1}_{A_M/k}), where AM=Ah/mMA_M=A^h/{\frak m}^M and m{\frak m} is the maximal ideal, is dominant for any qq for which the inverse Lefschetz operator H2dimXq(X)(dimX)Hq(X)(q)H^{2\dim X-q}(X)(\dim X)\stackrel{\sim}{\longrightarrow}H^q(X)(q) is induced by a correspondence.

Keywords

Cite

@article{arxiv.math/9812058,
  title  = {Refining the Abel--Jacobi maps},
  author = {M. Rovinsky},
  journal= {arXiv preprint arXiv:math/9812058},
  year   = {2007}
}

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6 pages