A relative Nadel-type vanishing theorem
Jingcao Wu
TL;DR
This work extends Nadel-type vanishing to a relative setting for fibrations $f:X\to Y$ by combining the relative asymptotic multiplier ideal $\mathscr{I}(f,\|L\|)$ with Nakano semi-positivity (and its strong singular analogue) to show vanishing of pushforwards $R^{q}f_{\ast}(K_{X}\otimes L\otimes E\otimes\mathscr{I}(f,\|L\|))$ for $q>l-\kappa(L,f)$. It also proves absolute and singular versions via the Monge–Ampère method and strong openness, yielding $H^{q}(X,K_{X}\otimes L\otimes E\otimes\mathscr{I}(\|L\|))=0$ or $H^{q}(X,K_{X}\otimes L\otimes E\otimes\mathcal{E}(h))=0$ for $q>n-\cdot$ where appropriate. A key technical backbone is a Mat22-style injectivity result that ensures torsion-freeness of the higher direct images, enabling extension from fibers and base change arguments. The paper then carries these ideas through a dimension-inductive strategy to treat $f$-nef and analytic almost base point free $L$, achieving the stated relative vanishing theorems and their corollaries for pushforwards along a fibration in the Kähler and projective settings.
Abstract
Let $f:X\rightarrow Y$ be a Kähler fibration from a complex manifold $X$ to an analytic space $Y$. We show several relative Nadel-type vanishing theorems.
