English

Positivity of direct images with a Poincar\'e type twist

Complex Variables 2020-05-05 v1 Algebraic Geometry Differential Geometry

Abstract

We consider a holomorphic family f:XSf:\mathcal{X} \to S of compact complex manifolds and a line bundle LX\mathcal{L}\to \mathcal{X}. Given that L1\mathcal{L}^{-1} carries a singular hermitian metric that has Poincar\'e type singularities along a relative snc divisor D\mathcal{D}, the direct image f(KX/SDL)f_*(K_{\mathcal{X}/S}\otimes \mathcal{D} \otimes \mathcal{L}) carries a smooth hermitian metric. In case L\mathcal{L} is relatively positive, we give an explicit formula for its curvature. The result applies to families of log-canonically polarized pairs. Moreover we show that it improves the general positivity result of Berndtsson-P\u{a}un in a special situation of a big line bundle.

Keywords

Cite

@article{arxiv.2005.01500,
  title  = {Positivity of direct images with a Poincar\'e type twist},
  author = {Philipp Naumann},
  journal= {arXiv preprint arXiv:2005.01500},
  year   = {2020}
}

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