The strong Novikov conjecture for low degree cohomology
The strong Novikov conjecture for low degree cohomology
We show that for each discrete group Γ, the rational assembly map $$K_*(B\Gamma) \otimes {\mathbb{Q}} \to K_*(C^*_{\max}\Gamma) \otimes {\mathbb{Q}}$$ is injective on classes dual to $${\Lambda^* \subset H^*(B\Gamma;\mathbb{Q})}$$ , where Λ* is the subring generated by cohomology classes of degree at most 2 (and where the pairing uses the Chern …