H-Space and Loop Space Structures for Intermediate Curvatures

Abstract

For dimensions $n\ge 3$ and $k\in \{2,\cdots ,n\}$, we show that the space of metrics of $k$-positive Ricci curvature on the sphere $S^n$ has the structure of an $H$-space with a homotopy commutative, homotopy associative product operation. We further show, using the theory of operads and results of Boardman, Vogt and May that the path component of this space containing the round metric is weakly homotopy equivalent to an $n$-fold loop space.

37 pages, 7 figures