English

Canonical growth conditions associated to ample line bundles

Algebraic Geometry 2018-02-21 v4 Complex Variables

Abstract

We propose a new construction which associates to any ample (or big) line bundle LL on a projective manifold XX a canonical growth condition (i.e. a choice of a psh function well-defined up to a bounded term) on the tangent space TpXT_p X of any given point pp. We prove that it encodes such classical invariants as the volume and the Seshadri constant. Even stronger, it allows you to recover all the infinitesimal Okounkov bodies of LL at pp. The construction is inspired by toric geometry and the theory of Okounkov bodies; in the toric case the growth condition is "equivalent" to the moment polytope. As in the toric case the growth condition says a lot about the K\"ahler geometry of the manifold. We prove a theorem about K\"ahler embeddings of large balls, which generalizes the well-known connection between Seshadri constants and Gromov width established by McDuff and Polterovich.

Keywords

Cite

@article{arxiv.1509.05528,
  title  = {Canonical growth conditions associated to ample line bundles},
  author = {David Witt Nyström},
  journal= {arXiv preprint arXiv:1509.05528},
  year   = {2018}
}

Comments

34 pages. Added outline of proofs for the big case