Author: Urs Format: MarkdownItexAdded the remark ([here](https://ncatlab.org/nlab/show/F-theory+on+Spin(7)-manifolds#RelationToJTwistedCohomotopy)) that $Spin(7)$-strucure on a Spin 8-manifold is equivalently a cocycle in J-twisted Cohomotopy
<a href="https://ncatlab.org/nlab/revision/diff/F-theory+on+Spin%287%29-manifolds/2">diff</a>, <a href="https://ncatlab.org/nlab/revision/F-theory+on+Spin%287%29-manifolds/2">v2</a>, <a href="https://ncatlab.org/nlab/show/F-theory+on+Spin%287%29-manifolds">current</a>
Added the remark (here) that -strucure on a Spin 8-manifold is equivalently a cocycle in J-twisted Cohomotopy