H^n_{dR}(M) = ker(d : Ω^n → Ω^{n+1}) / im(d : Ω^{n−1} → Ω^n) on a smooth manifold M. de Rham's theorem: isomorphic to singular cohomology with real coefficients.
H^n_{dR}(M) = ker(d : Ω^n → Ω^{n+1}) / im(d : Ω^{n−1} → Ω^n) on a smooth manifold M. de Rham's theorem: isomorphic to singular cohomology with real coefficients.