Theorem. Suppose that <math>M</math> is a three-dimensional complex manifold and <math>Omega</math> is the real part of a non-vanishing holomorphic 3-form, then <math>Omega</math> is a critical point of the functional <math>Phi</math> restricted to the cohomology class <math> in H^3(M,R)</math>. Conversely, if......