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Concept

Cohomologie galoisienne

Publications associées (10)

Cohomological Invariants for G-Galois Algebras and Self-Dual Normal Bases

Eva Bayer Fluckiger

Cohomological Invariants for G-Galois Algebras and Self-Dual Normal Bases. We define degree two cohomological invariants for

G

-Galois algebras over fields of characteristic not 2, and use them to give necessary conditions for the existence of a self--dua ...

2017

Some consequences of Masser's counting theorem on elliptic curves

We use Masser's counting theorem to prove a lower bound for the canonical height in powers of elliptic curves. We also prove the Galois case of the elliptic Lehmer problem, combining Kummer theory and Masser's result with bounds on the rank and torsion of ...

Springer Heidelberg2017

Invariant forms on irreducible modules of simple algebraic groups

Mikko Tapani Korhonen

Let G be a simple linear algebraic group over an algebraically dosed field K of characteristic p >= 0 and let V be an irreducible rational G-module with highest weight A. When is self-dual, a basic question to ask is whether V has a non-degenerate G-invari ...

Elsevier2017

The Hochschild complex of a twisting cochain

Kathryn Hess Bellwald

Given any twisting cochain t:C→A , where C is a connected, coaugmented chain coalgebra and A is an augmented chain algebra over an arbitrary commutative ring R, we construct a twisted extension of chain complexes Full-size image (1 K) of which both the wel ...

Elsevier2016

L-2-cohomology and complete Hamiltonian manifolds

Tudor Ratiu

A classical theorem of Frankel for compact Kahler manifolds states that a Kahler S-1-action is Hamiltonian if and only if it has fixed points. We prove a metatheorem which says that when the Hodge theory holds on non-compact manifolds, Frankel's theorem st ...

Elsevier2015

Some remarks on the two-variable main conjecture of Iwasawa theory for elliptic curves without complex multiplication

Jeanine Marie Van Order

We establish several results towards the two-variable main conjecture of Iwasawa theory for elliptic curves without complex multiplication over imaginary quadratic fields, namely (i) the existence of an appropriate p-adic L-function, building on works of H ...

2012

Singularities of generic characteristic polynomials and smooth finite splittings of Azumaya algebras over surfaces

Manuel Ojanguren

Let k be an algebraically closed field. Let P(X-11,...,X-nn, T) be the characteristic polynomial of the generic matrix (X-ij) over k. We determine its singular locus as well as the singular locus of its Galois splitting. If X is a smooth quasi-projective s ...

Springer-Verlag2009

Unitary descent properties

Eva Bayer Fluckiger

Let k be a field of characteristic /=2 and let W(k) be the Witt ring of k and L a finite extension of k. If L/k is a Galois extension, then the image of rL/k is contained in W(L)Gal(L/k) where rL/k:W(k)→W(L) is the canonical ring homomorphism. Rosenberg an ...

2009

Multiple of trace forms and algebras with involution

Eva Bayer Fluckiger

Let k be a field of characteristic

\neq

2, and let G be a finite group. The aim of this article is to give a cohomological criterion for the isomorphism of multiples of trace forms of G-Galois algebras over k. The proof uses results concerning multiples ...

Oxford University Press2007

Anneau de Witt des G-formes et multiples de G-formes trace

Philippe Chabloz

This thesis deals with the study of G-forms and particulary the trace form of a G-Galois algebra. Let k be a field of characteristic not two. Let G be a finite group and L a G-Galois algebra over k. We define the trace form qL by qL(x, y) = TrL/k(xy) for a ...

EPFL2004

Publications associées (10)

Cohomological Invariants for G-Galois Algebras and Self-Dual Normal Bases

Eva Bayer Fluckiger

Cohomological Invariants for G-Galois Algebras and Self-Dual Normal Bases. We define degree two cohomological invariants for

G

-Galois algebras over fields of characteristic not 2, and use them to give necessary conditions for the existence of a self--dua ...

2017

\neq

Oxford University Press2007

Anneau de Witt des G-formes et multiples de G-formes trace

Philippe Chabloz

EPFL2004