Wild Ramification in the Imperfect Residue Field Case
Wild Ramification in the Imperfect Residue Field Case
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不完美残基场案例中的疯狂后果
DOI:
10.2969/aspm/01210287
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发表时间:
1987
期刊:
影响因子:
--
通讯作者:
Osamu Hyodo
中科院分区:
文献类型:
--
作者:
Osamu Hyodo
The aim of this paper is to study wild ramification of complete discrete valuation fields without the assumption that the residue field is perfect. In the case where the residue field is perfect, there is a beautiful theory of ramification groups (Serre [14] §4). The difficulty of our case is that there seems to be no such a theory in general. As applications of our study, we shall show the following three results. In the following, let K be a complete discrete valuation field of mixed characteristics (0, p). (1) Miki [9], [10] studied ZP-extensions of K. He showed that any ZP-extension of K is contained in a composite of an unramified extension of K and a ZP-extension of the "canonical subfield" k of K. Here, k is characterized by the following properties.