The Structure of the Spin^h Bordism Spectrum

Abstract

Spin$^h$ manifolds are the quaternionic analogue to Spin$^c$ manifolds. We compute the spin$^h$ bordism groups at the prime 2 by proving a structure theorem for the cohomology of the spin$^h$ bordism spectrum $\mathrm{MSpin}^h$ as a module over the mod 2 Steenrod algebra. This provides a 2-local splitting of $\mathrm{MSpin}^h$ as a wedge sum of familiar spectra. We also compute the decomposition of $H^*(\mathrm{MSpin}^h;\mathbb{Z}/2\mathbb{Z})$ explicitly in degrees up through 30 via a counting process.