$L^2$-Dolbeault resolutions and Nadel vanishing on weakly pseudoconvex complex spaces with singular Hermitian metrics
Yuta Watanabe
TL;DR
This work develops a general $L^2$-theory for the $\overline{\partial}$-operator on complex spaces with singular Hermitian metrics by constructing $L^2$-Dolbeault fine resolutions and isomorphisms and proving global $L^2$-estimates on the regular locus. The authors establish a robust framework involving canonical desingularizations, curvature currents, and multiplier ideal sheaves (with strong openness) to extend Nadel vanishing to weakly pseudoconvex spaces, including compact and non-compact settings, without requiring a global Kähler metric. Their approach yields vanishing results for $H^q(X,\omega_X^{GR}(h)\otimes\mathcal{O}(L))$ under broad hypotheses (e.g., singular positive metrics and big or nef/big line bundles) and provides a bridge between $L^2$-cohomology on the regular locus and global cohomology via the $L^2$-Dolbeault isomorphism. This advances vanishing theorems on singular spaces and broadens applicability to Moishezon, complete-intersection, and non-Kähler contexts with potential implications for complex-analytic and birational geometry.
Abstract
In this paper, in order to develop a more general $L^2$-theory for the $\overline{\partial}$-operator on complex spaces, we provide $L^2$-Dolbeault fine resolutions and isomorphisms, and $L^2$-estimates, for holomorphic line bundles on complex spaces equipped with singular Hermitian metrics. As applications, we obtain several generalizations of the Nadel vanishing theorem.
