Reciprocity sheaves and abelian ramification theory.
Reciprocity sheaves and abelian ramification theory.
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互易滑轮和阿贝尔分枝理论。
DOI:
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发表时间:
2018
期刊:
影响因子:
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通讯作者:
S. Saito
中科院分区:
文献类型:
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作者:
Kay Rülling;S. Saito
We define a motivic conductor for any presheaf with transfers $F$ using the categorical framework developed for the theory of motives with modulus by Kahn-Saito-Yamazaki. If $F$ is a reciprocity sheaf this conductor yields an increasing and exhaustive filtration on $F(L)$, where $L$ is any henselian discrete valuation field of geometric type over the perfect ground field. We show if $F$ is a smooth group scheme, then the motivic conductor extends the Rosenlicht-Serre conductor; if $F$ assigns to $X$ the group of finite characters on the abelianized 'etale fundamental group of $X$, then the motivic conductor agrees with the Artin conductor defined by Kato-Matsuda; if $F$ assigns to $X$ the group of integrable rank one connections (in characteristic zero), then it agrees with the irregularity. We also show that this machinery gives rise to a conductor for torsors under finite flat group schemes over the base field, which we believe to be new. We introduce a general notion of conductors on presheaves with transfers and show that on a reciprocity sheaf the motivic conductor is minimal and any conductor which is defined only for henselian discrete valuation fields of geometric type with {em perfect} residue field can be uniquely extended to all such fields without any restriction on the residue field. For example the Kato-Matsuda Artin conductor is characterized as the canonical extension of the classical Artin conductor defined in the perfect residue field case.
影响因子:
2.5
作者:
Moritz Kerz;Shuji Saito
通讯作者:
Shuji Saito