Almost purity and overconvergent Witt vectors
نویسندگان
چکیده
منابع مشابه
Almost Purity for Overconvergent Witt Vectors
In a previous paper, we stated a general almost purity theorem in the style of Faltings: if R is a ring for which the Frobenius maps on finite p-typical Witt vectors over R are surjective, then the integral closure of R in a finite étale extension of R[p−1] is “almost” finite étale over R. Here, we use almost purity to lift the finite étale extension of R[p−1] to a finite étale extension of rin...
متن کاملOverconvergent Witt Vectors
Let A be a finitely generated algebra over a field K of characteristic p > 0. We introduce a subring W †(A) ⊂ W (A), which we call the ring of overconvergent Witt vectors and prove its basic properties. In a subsequent paper we use the results to define an overconvergent de Rham-Witt complex for smooth varieties over K whose hypercohomology is the rigid cohomology.
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The goal of this work is to construct, for a smooth variety X over a perfect field k of finite characteristic, an overconvergent de Rham-Witt complex W ΩX/k as a suitable subcomplex of the de RhamWitt complex of Deligne-Illusie. This complex, which is functorial in X, is a complex of étale sheaves and a differential graded algebra over the ring W (OX) of overconvergent Witt-vectors. If X is aff...
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Caution: These polynomials are referred to as w0, w1, w2, ... in Sections 5-8 of [1]. However, beginning with Section 9 of [1], Hazewinkel uses the notations w1, w2, w3, ... for some different polynomials (the so-called big Witt polynomials, defined by formula (9.25) in [1]), which are not the same as our polynomials w1, w2, w3, ... (though they are related to them: in fact, the polynomial wk t...
متن کاملLie powers and Witt vectors
In the study of Lie powers of a module V in prime characteristic p, a basic role is played by certain modules Bn introduced by Bryant and Schocker. The isomorphism types of the Bn are not fully understood, but these modules fall into infinite families {Bk,Bpk,Bp2k, . . .}, one family B(k) for each positive integer k not divisible by p, and there is a recursive formula for the modules within B(k...
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ژورنال
عنوان ژورنال: Journal of Algebra
سال: 2015
ISSN: 0021-8693
DOI: 10.1016/j.jalgebra.2014.08.055