Torsion algebraic cycles and étale cobordism
Torsion algebraic cycles and étale cobordism
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挠率代数环和étale协边
DOI：
10.1016/j.aim.2011.02.020
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发表时间：
2009
影响因子：
1.7
通讯作者：
Gereon Quick
中科院分区：
文献类型：
--
作者：
Gereon Quick
通过正特征代数闭域上的ℓ-Additale余边商，证明了从代数圈到上同调因子的经典积分圈类映射。这表明上同调类是代数的存在很强的拓扑障碍，Atiyah，Hirzebruch和Totaro的例子也是正特征的。
We prove that the classical integral cycle class map from algebraic cycles to étale cohomology factors through a quotient of ℓ-adic étale cobordism over an algebraically closed field of positive characteristic. This shows that there is a strong topological obstruction for cohomology classes to be algebraic and that examples of Atiyah, Hirzebruch and Totaro also work in positive characteristic.