For any reductive group G and a parabolic subgroup P with its Levi subgroup L, the first author in [Ku2] introduced a ring homomorphism $ \xi^P_\lambda: Rep^\mathbb{ C}_{ \lambda-poly}(L) \to H^*(G/P, \mathbb{ C})$, where $ Rep^\mathbb{ C}_{ \lambda-poly}(L)$ is a certain subring of the complexified representation ring of L (depending upon the choice of an irreducible representation $V(\lambda)$ of G with highest weight $\lambda$). In this paper we study this homomorphism for G=Sp(2n) and its maximal parabolic subgroups $P_{ n-k}$ for any $1\leq k\leq n$ (with the choice of $V(\lambda) $ to be the defining representation $V(\omega_1) $ in $\mathbb{ C}^{ 2n}$). Thus, we obtain a $\mathbb{ C}$-algebra homomorphism $ \xi_{ n,k}: Rep^\mathbb{ C}_{ \omega_1-poly}(Sp(2k)) \to H^*(IG(n-k, 2n), \mathbb{ C})$. Our main result asserts that $ \xi_{ n,k}$ is injective when n tends to $\infty$ keeping k fixed. Similar results are obtained for the odd orthogonal groups.
Categories: math.RT math.AT math.GR