Compact K\"ahler manifolds with nef anti-canonical bundle

Abstract

In this paper, we prove that a compact K\"ahler manifold $X$ with the nef anti-canonical bundle $-K_{X}$ admits a locally trivial fibration $\phi \colon X \to Y$, where the fiber $F$ is a rationally connected manifold and the base $Y$ is a Calabi--Yau manifold. We introduce a suitable approach that extends the strategy of Cao--H\"oring, originally developed for smooth projective varieties, to more general singular K\"ahler spaces. A key technical ingredient is a flatness criterion for pseudo-effective sheaves with vanishing first Chern class.