Let $X$ be a Kähler manifold with a simple normal crossing divisor $D$, i.e., pair $(X,D)$. Let $\omega$ and $\omega'$ be two Kähler forms in the same Kähler class then have we $dd^\mathbb{C}$-lemma on pair $(X,D)$?
2 Answers
If you take away $D$, then $X\setminus D$ is a non-compact complex manifold, so $\partial\bar{\partial}$-lemma in general does not hold in this case. However, by the work of Bott-Chern in 1965, for any complex manifold $M$, the $\partial\bar{\partial}$-lemma always holds for characteristic forms. For example, let $(E,h)\rightarrow M$ be a hermitian vector bundle and $c_k(E,h)$ be its canonical Chern form with respect to the hermitian metric $h$, then for any other Chern form $c_k(E,h')$, we have
$c_k(E,h)-c_k(E,h')=\partial\bar{\partial}\eta$
for some $\eta\in\Omega^{2k-2}(M)$. This is called double transgression in their paper and is the key point to generalize Nevanlinna's first main theorem to higher dimensions.
I think this partially answers your question. suppose $L\rightarrow X$ is the line bundle defined by $D\subset X$, then $L|(X\setminus D)\rightarrow X\setminus D$ can be equipped with a hermitian metric $h$, and the $\partial\bar{\partial}$-lemma holds for $c_1(L|X\setminus D,h)$. This can be regarded as the $\partial\bar{\partial}$-lemma for the paring $(X,D)$.
Addendum. Given the hermitian line bundle $(L,h)$ over $X$, let $s$ be a holomorphic section of $L$ with zero set $D$, the Poincare-Lelong formula can be written as
$dd^\mathbb{C}(\log||s||^2)=-c_1(L,h)+[D]$,
the equation holds in the sense of currents. Note that this is simply a generalization of the expression of the first Chern class using a nowhere vanishing section.
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$\begingroup$ So you mean $Ric(\omega)-Ric(\omega')=\partial\bar\partial \varphi$? on $X\setminus D$. And what about such lemma on pair $(X,D)$ instead $X\setminus D$ $\endgroup$– AlonCommented Oct 5, 2015 at 14:10
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$\begingroup$ @Alon If you are familiar with the Poincare-Lelong equation, my answer already gives what you want. $\endgroup$– YHBKJCommented Oct 5, 2015 at 16:04
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$\begingroup$ Can you explicitly writ it down, I can not sse how can you get it from poincare-lelong equation $\endgroup$– AlonCommented Oct 5, 2015 at 23:01
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We have $dd^c$ lemma for pair $(X,D)$, here we assume divisor $D$ is simple normal crossing and has conical singularities. In fact if two forms $\omega$ and $\omega'$ be in the same class then $\omega=\omega'+\sqrt{-1}\partial\bar\partial\varphi^D$ where $\varphi^D$ is related to Donaldson's linear theory see Simon's paper
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$\begingroup$ YHBKJ need to revise his answer $\endgroup$– user21574Commented Nov 28, 2015 at 13:59