Twistors, Self-Duality, and Spin Structures
arXiv:2108.01739 · doi:10.3842/SIGMA.2021.102
Abstract
The fact that every compact oriented 4-manifold admits spin structures was proved long ago by Hirzebruch and Hopf. However, the usual proof is neither direct nor transparent. This article gives a new proof using twistor spaces that is simpler and more geometric. After using these ideas to clarify various aspects of four-dimensional geometry, we then explain how related ideas can be used to understand both spin and spin structures in any dimension.