G. Mukherjee et P. Sankaran, ELEMENTARY ABELIAN 2-GROUP ACTIONS ON FLAG MANIFOLDS AND APPLICATIONS, Proceedings of the American Mathematical Society, 126(2), 1998, pp. 595-606
Let N- denote the unoriented cobordism ring. Let G = (Z/2)(n) and let
Z()(G) denote the equivariant cobordism ring of smooth manifolds wit
h smooth G-actions having finite stationary points. In this paper we s
how that the unoriented cobordism class of the (real) flag manifold M
= O(m)/(O(m(1)) X...X O(m(s))) is in the subalgebra generated by +(i<2
n) Ni, where m = Sigma m(j), and 2(n-1) < m less than or equal to 2(n)
. We obtain sufficient conditions for indecomposability of an element
in Z()(G). We also obtain a sufficient condition for algebraic indepe
ndence of any set of elements in Z()(G). Using our criteria, we const
ruct many indecomposable elements in the kernel of the forgetful map Z
(d)(G) --> N-d in dimensions 2 less than or equal to d < n, for n > 2,
and show that they generate a polynomial subalgebra of Z()(G).