Definite arithmetische Gruppen.
Degeneration of the Kummer sequence in characteristic
We study a deformation of the Kummer sequence to the radicial sequence over an -algebra, which is somewhat dual for the deformation of the Artin-Schreier sequence to the radicial sequence, studied by Saidi. We also discuss some relations between our sequences and the embedding of a finite flat commutative group scheme into a connected smooth affine commutative group schemes, constructed by Grothendieck.
Degree three cohomological invariants of semisimple groups
We study the degree 3 cohomological invariants with coefficients in of a semisimple group over an arbitrary field. A list of all invariants of adjoint groups of inner type is given.
Del Pezzo surfaces of degree four
Die Relationenfaktorgruppen von Stickelberger-Elementen und Kreiszahlen.
Die Struktur der absoluten Galoisgruppe über dem Körper R (t).
Dividing rational points on abelian varieties of CM-type
Divisible subgroups of Brauer groups and trace forms of central simple algebras.
Effective lifting of 2-cocycles for Galois cohomology
We give explicit formulas for reducing the problem of determining whether a given 2-cocycle is a coboundary and if so finding a lifting 1-cochain to a system of norm equations.
Einbettungsprobleme und Galoisstruktur lokaler Körper.
Erratum. Quelques remarques sur le -invariant
Essential dimension: A functorial point of view (after A. Merkurjev).
Exercises dyadiques.
Explicit solutions to embedding problems associated to orthogonal Galois representations.
Extensions centrales de groupes algébriques simplement connexes et cohomologie galoisienne
Extensions non abéliennes de degré d’un corps de nombres : étude locale-globale
Fields of Cohomological 2-Dimension Three.
Fractions rationnelles invariantes
From p-rigid elements to valuations (with a Galois-characterization of p-adic fields).
Galois cohomology of biquadratic extensions.