Note on restriction maps of Chow rings to Weyl group invariants

Abstract

Let G be an algebraic group corresponding to a compact Lie group. We study the restiction map from the Chow ring CH(BG) to the Wely group invariants CH(BT)^W. For example, we note that if G is simply connect and H(G) has torsion, then the restriction map is always not surjective.