Let $(M,\Omega)$ be a compact Kahler complex manifold of dimension $n$ and let $f,g:M\to \mathbb C$ be two $C^\infty$ functions with the following two propewrties:
$\int_M f\Omega=\int_M g\Omega$
$\Delta_{\bar{\partial}}(f)=\Delta_{\bar{\partial}}(g)$. Where $\Delta_{\bar{\partial}}$ is the usual $\bar{\partial}$-Laplacian constructed by the Hodge $\star$ operator. (However here I suppose that it is enough to assume that $\partial\bar\partial f=\partial\bar\partial g$)
How can I conclude from the above hypotheses that $f=g$?
Note that $\Delta_{\bar\partial} (f-g) = 0$, this implies that $f-g$ is harmonic and thus constant by compactness. The first condition then implies $f=g$.