Embeddings of maximal tori in classical groups, odd degree descent and Hasse principles

Autor: Eva Bayer-Fluckiger, Ting-Yu Lee, Raman Parimala
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Popis: The aim of this paper is to revisit the question of local-global principles for embeddings of \'etale algebras with involution into central simple algebras with involution over global fields of characteristic not 2. A necessary and sufficient condition is given in [BLP 18]. In the present paper, we give a simpler description of the obstruction group. It is also shown that if the etale algebra is a product of pairwise linearly disjoint field extensions, then the Hasse principle holds, and that if an embedding exists after an odd degree extension, then it also exists over the global field itself. An appendix gives a generalization of this later result, in the framework of a question of Burt Totaro.
Comment: This supersedes the preprint arXiv:2005.06996
Databáze: OpenAIRE