2014/03/18 by Mathieu Huruguen, Huruguen, Mathieu · 2 citations
Mathematics · #Algebraic Geometry (math.AG) #FOS: Mathematics #math.AG
paper · pdf · doi:10.48550/arxiv.1403.4348
21 pages. Comments welcome
arxiv created 2014/03/18 · arxiv updated 2014/03/19
A linear algebraic group G defined over a field k is called special if every G-torsor over every field extension of k is trivial. In 1958 Grothendieck classified special groups in the case where the base field is algebraically closed. In this paper we describe the derived subgroup and the coradical of a special reductive group over an arbitrary field k. We also classify special semisimple groups, special reductive groups of inner type and special quasisplit reductive groups over an arbitrary field k.