English

Twisting by a torsor

Algebraic Geometry 2015-08-13 v1

Abstract

Twisting by a G-torsor an object endowed with an action of a group G is a classical tool. For instance one finds in the paragraph 5.3 of the book "cohomologie galoisienne" by Serre, the description of the "op\'eration de torsion" in a particular context. The aim of this note is to give a formalization of this twisting operation as general as possible in the algebraic geometric framework and to present a few applications. We will focus in particular to the application to the problem of specialization of covers addressed by P. D\`ebes and al. in a series of papers.

Keywords

Cite

@article{arxiv.1508.02903,
  title  = {Twisting by a torsor},
  author = {Michel Emsalem},
  journal= {arXiv preprint arXiv:1508.02903},
  year   = {2015}
}
R2 v1 2026-06-22T10:32:04.339Z