I see in my course the following theorem:
If $\omega$ is an exact k-form over an oriented compact manifold M of dimension $k$, then $\int_M \omega=0$.
I don't have a proof of this theorem and I only know it's an application of stokes theorem.
Is this theorem correct?
Thank you for any help.
Best Answer
$$ \text{With }\omega = d\eta, \qquad \int_M \omega = \int_M d\eta = \int_{\partial M} \eta = 0 \quad \text{since }M \text{ has no boundary.}$$