Enlargeable Length-structures and Scalar Curvatures
arXiv:1907.03135 · doi:10.1007/s10455-021-09772-7
Abstract
We define enlargeable length-structures on closed topological manifolds and then show that the connected sum of a closed -manifold with an enlargeable Riemannian length-structure with an arbitrary closed smooth manifold carries no Riemannian metrics with positive scalar curvature. We show that closed smooth manifolds with a locally CAT(0)-metric which is strongly equivalent to a Riemannian metric are examples of closed manifolds with an enlargeable Riemannian length-structure. Moreover, the result is correct in arbitrary dimensions based on the main result of a recent paper by Schoen and Yau. We define the positive -scalar curvature on closed orientable topological manifolds and show the compactly enlargeable length-structures are the obstructions of its existence.
Change the title and to appear in Annals of Global Analysis and Geometry