20 septembre 2024
Université de Lille
Fuseau horaire Europe/Paris

The Kato-Milne cohomology group of a rational function field.

20 sept. 2024, 15:05
25m
Salle de réunion, Bâtiment M2, Cité Scientifique (Université de Lille)

Salle de réunion, Bâtiment M2, Cité Scientifique

Université de Lille

Laboratoire Paul Painlevé Université de Lille Bâtiment M2, Cité Scientifique 59655 VILLENEUVE D'ASCQ Cedex FRANCE

Orateur

Mme T. Maiti (LML)

Description

Let F be a field of characteristic 2. The Kato-Milne cohomology group of F of degree m is denoted by H_2^{m+1}(F). This is an important group for the study of quadratic forms in characteristic 2 as was shown in a celebrated result due to Kato. Our aim in this talk is to give a complete description of the group H_2^{m+1}(F(t)) of the rational function field F(t). This will be done in terms of thegroup H_2^{m+1}(F) and some residue groups corresponding to simple finite extensions of F. As an application, we prove that the kernel of the homomorphism H_2^{m+1}(F) − −− > H_2^{m+1}(F(p)), induced by scalar extension, coincides with the annihilator of the logarithmic differential form dp/p, where F(p) is the function field of the affine hypersurface given by an arbitrary irreducible and normed polynomial p. This talk is a part of my PhD thesis supervised by Ahmed Laghribi (LML, Universit´e d’Artois).

Documents de présentation

Aucun document.