English

Test configurations and Okounkov bodies

Complex Variables 2019-02-20 v1 Algebraic Geometry

Abstract

We associate to a test configuration of an ample line bundle a filtration of the section ring of the line bundle. Using the recent work of Boucksom-Chen we get a concave function on the Okounkov body whose law with respect to Lebesgue measure determines the asymptotic distribution of the weights of the test configuration. We show that this is a generalization of a well-known result in toric geometry. As an application, we prove that the pushforward of the Lebesgue measure on the Okounkov body is equal to a Duistermaat-Heckman measure of a certain deformation of the manifold. Via the Duisteraat-Heckman formula, we get as a corollary that in the special case of an effective C×\mathbb{C^{\times}}-action on the manifold lifting to the line bundle, the pushforward of the Lebesgue measure on the Okounkov body is piecewise polynomial.

Keywords

Cite

@article{arxiv.1001.3286,
  title  = {Test configurations and Okounkov bodies},
  author = {David Witt Nystrom},
  journal= {arXiv preprint arXiv:1001.3286},
  year   = {2019}
}

Comments

24 pages

R2 v1 2026-06-21T14:36:33.793Z