Problems / geometry-topology
geometry-topology / Scalar curvature; simplicial volume and bounded cohomology
Gromov's integral scalar-curvature bound for simplicial volume
Theorem 1.1: for every n≥3 there is an>0 with ∫M(Scalg−)n/2dVg≥an∥M∥ for every closed connected oriented smooth n-manifold M and smooth metric g; e.g. Scalg≥−n(n−1) gives Volg(M)≥an[n(n−1)]−n/2∥M∥. The route is a Yamabe reduction to Scal=−1 followed by a bounded-cohomology and graph-deformation estimate. No explicit value of an is stated in the theorem, and dimension two is excluded.