Tits p‐indexes of semisimple algebraic groups

Abstract

The first author has recently shown that semisimple algebraic groups are classified up to motivic equivalence by the local versions of the classical Tits indexes over field extensions, known as Tits p-indexes. We provide in this article the complete description of the values of the Tits p-indexes over fields. From this exhaustive study, we also deduce criteria for motivic equivalence of semisimple groups of many types, hence giving a dictionary between classic algebraic structures, representation theory, cohomological invariants, and Chow motives of the twisted flag varieties for those groups.