scholarly journals Global Norm-Residue Map over Quasi-Finite Field

1966 ◽  
Vol 27 (1) ◽  
pp. 323-329 ◽  
Author(s):  
D. S. Rim ◽  
G. Whaples

A field k is called quasi-finite if it is perfect and if Gk≈Ż where Gk is the Galois group of the algebraic closure kc over k and Ż is the completion of the additive group of the rational integers. The classical reciprocity law on the local field with finite residue field is well-known to hold on local fields with quasi-finite residue field ([4] [5]). Thus it is natural to ask if the global reciprocity law should hold in the ordinary sense (see § 1 below) on the function-fields of one variable over quasi-finite field. We consider here two basic prototypes of non-finite quasi-finite fields:

Author(s):  
S. D. Cohen

AbstractFor a polynomial f(x) over a finite field Fq, denote the polynomial f(y)−f(x) by ϕf(x, y). The polynomial ϕf has frequently been used in questions on the values of f. The existence is proved here of a polynomial F over Fq of the form F = Lr, where L is an affine linearized polynomial over Fq, such that f = g(F) for some polynomial g and the part of ϕf which splits completely into linear factors over the algebraic closure of Fq is exactly φF. This illuminates an aspect of work of D. R. Hayes and Daqing Wan on the existence of permutation polynomials of even degree. Related results on value sets, including the exhibition of a class of permutation polynomials, are also mentioned.


1999 ◽  
Vol 42 (1) ◽  
pp. 78-86 ◽  
Author(s):  
Josep González

AbstractWe study the splitting of Fermat Jacobians of prime degree l over an algebraic closure of a finite field of characteristic p not equal to l. We prove that their decomposition is determined by the residue degree of p in the cyclotomic field of the l-th roots of unity. We provide a numerical criterion that allows to compute the absolutely simple subvarieties and their multiplicity in the Fermat Jacobian.


Author(s):  
R. Toledano

In this paper, we introduce the notions of [Formula: see text]-polynomial and [Formula: see text]-minimal value set polynomial where [Formula: see text] is a polynomial over a finite field [Formula: see text] and [Formula: see text] is a finite subset of an algebraic closure of [Formula: see text]. We study some properties of these polynomials and we prove that the polynomials used by Garcia, Stichtenoth and Thomas in their work on good recursive tame towers are [Formula: see text]-minimal value set polynomials for [Formula: see text], whose [Formula: see text]-value sets can be explicitly computed in terms of the monomial [Formula: see text].


2019 ◽  
Vol 20 (02) ◽  
pp. 2050008
Author(s):  
Yatir Halevi ◽  
Assaf Hasson ◽  
Franziska Jahnke

We initiate the study of definable [Formula: see text]-topologies and show that there is at most one such [Formula: see text]-topology on a [Formula: see text]-henselian NIP field. Equivalently, we show that if [Formula: see text] is a bi-valued NIP field with [Formula: see text] henselian (respectively, [Formula: see text]-henselian), then [Formula: see text] and [Formula: see text] are comparable (respectively, dependent). As a consequence, Shelah’s conjecture for NIP fields implies the henselianity conjecture for NIP fields. Furthermore, the latter conjecture is proved for any field admitting a henselian valuation with a dp-minimal residue field. We conclude by showing that Shelah’s conjecture is equivalent to the statement that any NIP field not contained in the algebraic closure of a finite field is [Formula: see text]-henselian.


Author(s):  
Olga Yu. Ivanova ◽  
◽  
Igor B. Zhukov ◽  

The article contributes to the theory of elimination of wild ramification for 2-dimensional local fields. It continues the study of classification of complete discrete valuation fields introduced in the work of Masato Kurihara. The main object of study is a 2-dimensional local field K of mixed characteristic with a finite residue field of odd characteristic. If such a field is weakly unramified over its constant subfield k (the maximal usual local field inside it), i. e., if eK/k = 1, its structure is well known. It is also known that any 2-dimensional local field can be turned into a standard one by means of a finite extension of its constant subfield (Epp’s theorem). However, the estimate of the minimal degree of such extension is an open question in general. In Kurihara’s article the 2-dimensional are subdivided into 2 types as follows. Consider a non-trivial linear relation between differentials of the two local parameters of the field. The field belongs to Type I, if the valuation of the coefficient by the uniformizer is less than that by the second local parameter, and to Type II otherwise. This paper is devoted to the fields of Type II. For them we consider the invariant Δ, the difference between valuations of coefficients in the above mentioned linear relation (it is non-positive for the fields of Type II). The minimal degree of the required extension of k cannot be less than eK/k for trivial reasons. However, such extension of degree eK/k does not exist in general. In this article it is proved that it exists if the absolute value of Δ is sufficiently large. The corresponding estimate for Δ depends only on eK/k.


2017 ◽  
Vol 82 (3) ◽  
pp. 1132-1139 ◽  
Author(s):  
ÖZLEM BEYARSLAN ◽  
ZOÉ CHATZIDAKIS

AbstractWe study the automorphism group of the algebraic closure of a substructure A of a pseudo-finite field F, or more generally, of a bounded PAC field F. This paper answers some of the questions of [1], and in particular that any finite group which is geometrically represented in a pseudo-finite field must be abelian.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Carlos A. M. André ◽  
João Dias

Abstract We consider smooth representations of the unit group G = A × G=\mathcal{A}^{\times} of a finite-dimensional split basic algebra 𝒜 over a non-Archimedean local field. In particular, we prove a version of Gutkin’s conjecture, namely, we prove that every irreducible smooth representation of 𝐺 is compactly induced by a one-dimensional representation of the unit group of some subalgebra of 𝒜. We also discuss admissibility and unitarisability of smooth representations of 𝐺.


2012 ◽  
Vol 77 (4) ◽  
pp. 1057-1066 ◽  
Author(s):  
Özlem Beyarslan ◽  
Ehud Hrushovski

AbstractWe study the automorphism group of the algebraic closure of a substructureAof a pseudo-finite fieldF. We show that the behavior of this group, even whenAis large, depends essentially on the roots of unity inF. For almost all completions of the theory of pseudofinite fields, we show that overA, algebraic closure agrees with definable closure, as soon asAcontains the relative algebraic closure of the prime field.


2012 ◽  
Vol 55 (2) ◽  
pp. 418-423 ◽  
Author(s):  
Le Anh Vinh

AbstractGiven a positive integern, a finite fieldofqelements (qodd), and a non-degenerate symmetric bilinear formBon, we determine the largest possible cardinality of pairwiseB-orthogonal subsets, that is, for any two vectorsx,y∈ Ε, one hasB(x,y) = 0.


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