Unramified Brauer groups of finite simple groups of lie type A(e)

摘要

We study the subgroup B-0(G) of H-2(G, Q/Z) consisting of all elements which have trivial restrictions to every Abelian subgroup of G. The group B-0(G) serves as the simplest nontrivial obstruction to stable rationality of algebraic varieties V/G where V is a faithful complex linear representation of the group G. We prove that B-0(G) is trivial for finite simple groups of Lie type A(l).