English

${\cal H}$-cohomologies versus algebraic cycles

alg-geom 2008-02-03 v1 Algebraic Geometry

Abstract

Global intersection theories for smooth algebraic varieties via products in {\it appropriate}\, Poincar\'e duality theories are obtained. We assume given a (twisted) cohomology theory HH^* having a cup product structure and we let consider the H{\cal H}-cohomology functor XHZar#(X,H)X\leadsto H^{\#}_{Zar}(X,{\cal H}^*) where H{\cal H}^* is the Zariski sheaf associated to HH^*. We show that the H{\cal H}-cohomology rings generalize the classical ``intersection rings'' obtained via rational or algebraic equivalences. Several basic properties e.g.\, Gysin maps, projection formula and projective bundle decomposition, of H{\cal H}-cohomology are obtained. We therefore obtain, for XX smooth, Chern classes cp,i:Ki(X)Hpi(X,Hp)c_{p,i} : K_i(X) \to H^{p-i}(X,{\cal H}^p) from the Quillen KK-theory to H{\cal H}-cohomologies according with Gillet and Grothendieck. We finally obtain the ``blow-up formula'' Hp(X,Hq)Hp(X,Hq)i=0c2Hp1i(Z,Hq1i)H^p(X',{\cal H}^q) \cong H^p(X,{\cal H}^q)\oplus \bigoplus_{i=0}^{c-2} H^{p-1-i}(Z,{\cal H}^{q-1-i}) where XX' is the blow-up of XX smooth, along a closed smooth subset ZZ of pure codimension cc. Singular cohomology of associated analityc space, \'etale cohomology, de Rham and Deligne-Beilinson cohomologies are examples for this setting.

Keywords

Cite

@article{arxiv.alg-geom/9408002,
  title  = {${\cal H}$-cohomologies versus algebraic cycles},
  author = {Luca Barbieri-Viale},
  journal= {arXiv preprint arXiv:alg-geom/9408002},
  year   = {2008}
}

Comments

51 pages, LaTeX 2.09

R2 v1 2026-07-22T07:41:31.125Z