A Kähler manifold is a complex manifold with a positive real closed -form . The associated Riemannian metric is .
The Lefschetz operator of a Kähler manifold is exterior multiplication by its Kähler form,Its formal adjoint is denoted by and lowers the bidegree of a differential form by .
The Fubini-Study form is the standard Kähler form on complex projective space. With the integral normalization, .