S1-Equivariant bordism, invariant metrics of positive scalar curvature, and rigidity of elliptic genera
S1-Equivariant bordism, invariant metrics of positive scalar curvature, and rigidity of elliptic genera
We construct geometric generators of the effective $S^1$-equivariant Spin- (and oriented) bordism groups with two inverted. We apply this construction to the question of which $S^1$-manifolds admit invariant metrics of positive scalar curvature. It turns out that, up to taking connected sums with several copies of the same manifold, the …