Let $M$ be a smooth manifold (not necessarily orientable) and let $N=\partial M$. Is $N$ necessarily orientable?
I have no particular reason to believe that this is the case, but I wasn't able to come up with a counterexample either.
Let $M$ be a smooth manifold (not necessarily orientable) and let $N=\partial M$. Is $N$ necessarily orientable?
I have no particular reason to believe that this is the case, but I wasn't able to come up with a counterexample either.
I'm a bit rusty on this but would not something like $M\times [0,1)$ be a counterexample? (where $M$ is the Möbius band)