Vanishing theorems and rational connectedness on holomorphic tensor fields

TL;DR

This paper proves a vanishing theorem for certain positive Hermitian vector bundles and applies it to show that specific K"{a}hler manifolds are projective and rationally connected, extending recent results in complex geometry.

Contribution

It establishes a new vanishing theorem for uniformly RC $k$-positive bundles and links positive curvature conditions to rational connectedness of K"{a}hler manifolds.

Findings

Holomorphic tensor fields are trivial under certain positivity conditions.

Compact K"{a}hler} manifolds with positive $k$-Ricci curvature are projective.

Such manifolds are also rationally connected.

Abstract

A vanishing theorem for uniformly RC $k$-positive Hermitian holomorphic vector bundles is established. It turns out that the holomorphic tangent bundle of a compact complex manifold equipped with a positive $k$-Ricci curvature K\"{a}hler metric is uniformly RC $k$-positive. Two main applications are presented. The first one is to deduce that spaces of some holomorphic tensor fields on such K\"{a}hler or more generally K\"{a}hler-like Hermitian manifolds are trivial, generalizing some recent results. The second one is to show that a compact K\"{a}hler manifold whose holomorphic tangent bundle can be endowed with either a uniformly RC $k$-positive Hermitian metric or a positive $k$-Ricci curvature K\"{a}hler-like Hermitian metric is projective and rationally connected.