In particular he proved theorems about the embedding of an n-dimensional differentiable manifold in Euclidean space and he discovered characteristic classes at the same time as Stiefel.
Sa mga partikular na siya proved theorems tungkol sa-embed ng isang n-dimensional differentiable sari-sari sa Euclidean space at siya natuklasan katangian klase sa parehong panahon bilang Stiefel.