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arXiv 1806.03096math.AG
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数域上格式的混合合$\ell$-adic复形

Mixed $\ell$-adic complexes for schemes over number fields

Sophie Morel

AI总结:

本文针对数域上的格式,定义了水平ℓ进复形与周层,并指出混合周层一般无权滤过,通过直接在有权滤过的周层导出范畴中工作,将中间扩张计算方法推广到有限生成域。

摘要:

若$X$是数域上的代数簇,安妮特·胡贝尔(Annette Huber)已在$X$上定义了一类“水平的”(或称“几乎处处非分歧的”)$\ell$进复形与$\ell$进反常层的范畴。对于这类对象,权的概念(按德利涅(Deligne)的定义)是有意义的,这与有限域上代数簇的情形一致。但与有限域的情况不同,$X$上的混合反常层(或混合局部常值层)一般不具有权滤过,即便$X$是一个点时也是如此。本文的目标是说明如何通过直接在具有权滤过的反常层的阿贝尔范畴的导出范畴中开展研究,来规避这一问题。作为应用,作者此前一篇论文中用于计算纯净反常层的中间扩张的方法,可适用于任意有限生成域,而不仅限于有限域。

英文摘要:

If $X$ is a variety over a number field, Annette Huber has defined a category of "horizontal" (or "almost everywhere unramified") $\ell$-adic complexes and $\ell$-adic perverse sheaves on $X$. For such objects, the notion of weights makes sense (in the sense of Deligne), just as in the case of varieties over finite fields. However, contrary to what happens in that last case, mixed perverse sheaves (or mixed locally constant sheaves) on $X$ do not have a weight filtration in general, even when $X$ is a point. The goal of this paper is to show how to avoid this problem by working directly in the derived category of the abelian category of perverse sheaves that do admit a weight filtration. As an application, the methods of a previous paper of the author to calculate the intermediate extension of a pure perverse sheaf apply over any finitely generated field, and not just over a finite field.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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