Proof of a conjecture of Whitney
Proof of a conjecture of Whitney
Let M be a closed, connected, nonorientable surface of Euler characteristic X which is smoothly embedded in Euclidean 4-space, R 4 , with normal bundle v.The Euler class of i>, denoted by e(v), is an element of the cohomology group H 2 (M; %) (the letter % denotes twisted integer …