 Whitney product formula for Stiefel–Whitney classes

ID: whitney-product-formula-for-stiefel-whitney-classes

E

and

F

w (E \oplus F) = w (E) w (F), w_{k} (E \oplus F) = \sum_{i + j = k} w_{i} (E) w_{j} (F) .

After applying the splitting principle for real vector bundles, both sides are the product of

1 + w_{1} (L)

over all line summands.

 New to topics? Read the docs here!