Ramification of local fields with imperfect residue fields
نویسندگان
چکیده
We define two decreasing filtrations by ramification groups on the absolute Galois group of a complete discrete valuation field whose residue field may not be perfect. In the classical case where the residue field is perfect, we recover the classical upper numbering filtration. The definition uses rigid geometry and log-structures. We also establish some of their properties.
منابع مشابه
Ramification Theory for Local Fields with Imperfect Residue Fields
Notation 1.1. Let l/k be a finite Galois extension of complete discretely valued fields. Let Ok, Ol, πk, πl, k̄, and l̄ be rings of integers, uniformizers, and residue fields, respectively. For an element a ∈ Ol, we use ā to denote its reduction in l̄. Let G = Gl/k be the Galois group. Use vl(·) to denote the valuation on l so that vl(πl) = 1. We call e = vl(πk) the näıve ramification degree; it i...
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تاریخ انتشار 2008