Hard Lefschetz isomorphism on Dolbeault cohomology (source code)

= Hard Lefschetz isomorphism on Dolbeault cohomology
{title2=$L^{n-p-q}:H_{\bar\partial}^{p,q}\cong H_{\bar\partial}^{n-q,n-p}\quad(p+q\le n)$}

On a compact <Kähler manifold>, the <Lefschetz operator preserves harmonic forms>, so the indicated power acts on harmonic representatives of <Dolbeault cohomology>. It is injective by <injectivity of powers of the Lefschetz operator>; <Hodge symmetry> and <Hodge duality> make its finite-dimensional source and target have equal dimension, so it is an isomorphism.