Let \(M\) and \(N\) be smooth manifolds, and let \(f:M\to N\) be smooth. Prove that if \(\theta \) and \(\psi \) are closed differentiable \(n\)-forms on \(N\) (so that \([\theta ]\) and \([\psi ]\) are classes in de Rham cohomology) then \([\theta ]=[\psi ]\) implies \([f^*\theta ]=[f^*\psi ]\).
Question
Math 6510 • Differentiable Manifolds
Spring 2018 • Question 6