论文标题
部分可观测时空混沌系统的无模型预测
Sur l'injectivité de l'application cycle de Jannsen
论文作者
论文摘要
对于特定类别的平滑,投射品种$ x $在字段$ k $上的$ x $,我们比较了第二个Chow组的Torsion子组$ CH^2(x)_ {\ text {tors}} $上的两个周期地图。第一个回到S. Bloch(1981)的作品,第二个是Jannsen的周期图中的连续$ \ ell $ - ad-adic的共同体,其注射效率在最近的两篇论文中引起了人们的关注。一方面,比较给出了足够的假设,以确保詹森周期地图的注入性发送$ ch^2(x)$至$ h^4_ {cont}(x,x,z _ {\ ell}(\ ell}(\ ell}(2))($ \ ell $ - elly $ - ell-ell $ - 优先扭转)。另一方面,使用反例来注入第一份图和第一作者(1983年),我们在一个变量的一个变量中为$ \ ell = 2 $在一个完全想象的数字字段中提供了平滑,投影,几何,几何理性的表面的示例,在一个完全想象的数字字段中,这不是$ \ ell = 2 $的$ 2美元。这回答了最近的一篇论文提出的问题。
For specific classes of smooth, projective varieties $X$ over a field $k$, we compare two cycle maps on the torsion subgroup $CH^2(X)_{\text{tors} }$ of the second Chow group. The first one goes back to work of S. Bloch (1981), the second one is Jannsen's cycle map into continuous $\ell$-adic cohomology, whose injectivity properties have attracted attention in two recent papers. On the one hand, the comparison gives sufficient hypotheses to guarantee injectivity of Jannsen's cycle map sending $CH^2(X)$ to $H^4_{cont}(X, Z_{\ell}(2))$ on $\ell$-primary torsion. On the other hand, using counterexamples to injectivity of the first map due to Sansuc and the first author (1983), we give examples of smooth, projective, geometrically rational surfaces over a rational function field in one variable over a totally imaginary number field for which Jannsen's map for $\ell=2$ is not injective on $2$-torsion. This answers questions raised in a recent paper.