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Factorisability and wildly ramified Galois extensions

David J. Burns (1991)

Annales de l'institut Fourier

Let L / K be an abelian extension of p -adic fields, and let 𝒪 denote the valuation ring of K . We study ideals of the valuation ring of L as integral representations of the Galois group Gal ( L / K ) . Assuming K is absolutely unramified we use techniques from the theory of factorisability to investigate which ideals are isomorphic to an 𝒪 -order in the group algebra K [ Gal ( l / K ) ] . We obtain several general and also explicit new results.

Factorisation d'opérateurs différentiels à coefficients dans une extension liouvillienne d'un corps valué

Magali Bouffet (2002)

Annales de l’institut Fourier

On démontre ici un lemme de Hensel pour les opérateurs différentiels. On en déduit un théorème de factorisation pour des opérateurs différentiels à coefficients dans une extension liouvillienne transcendante d’un corps valué. On obtient en particulier un théorème de factorisation pour des opérateurs différentiels à coefficients dans une extension de ( ( z ) ) par un nombre fini d’exponentielles et de logarithmes algébriquement indépendants sur ( ( z ) ) .

Factorization in Krull monoids with infinite class group

Florian Kainrath (1999)

Colloquium Mathematicae

Let H be a Krull monoid with infinite class group and such that each divisor class of H contains a prime divisor. We show that for each finite set L of integers ≥2 there exists some h ∈ H such that the following are equivalent: (i) h has a representation h = u 1 · . . . · u k for some irreducible elements u i , (ii) k ∈ L.

Factorization of matrices associated with classes of arithmetical functions

Shaofang Hong (2003)

Colloquium Mathematicae

Let f be an arithmetical function. A set S = x₁,..., xₙ of n distinct positive integers is called multiple closed if y ∈ S whenever x|y|lcm(S) for any x ∈ S, where lcm(S) is the least common multiple of all elements in S. We show that for any multiple closed set S and for any divisor chain S (i.e. x₁|...|xₙ), if f is a completely multiplicative function such that (f*μ)(d) is a nonzero integer whenever d|lcm(S), then the matrix ( f ( x i , x i ) ) having f evaluated at the greatest common divisor ( x i , x i ) of x i and x i as its...

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