English

4-dimensional symplectic contractions

Algebraic Geometry 2013-03-14 v2

Abstract

Local symplectic contractions are resolutions of singularities which admit symplectic forms. Four dimensional symplectic contractions are (relative) Mori Dream Spaces. In particular, any two such resolutions of a given singularity are connected by a sequence of Mukai flops. We discuss the cone of movable divisors on such a resolution; its faces are determined by curves whose loci are divisors, we call them essential curves. The movable cone is divided into nef chambers which are related to different resolutions; this subdivision is determined by classes of 1-cycles. We also study schemes parametrizing minimal essential curves and show that they are resolutions, possibly non-minimal, of surface Du Val singularities. Some examples, with an exhaustive description, are provided.

Keywords

Cite

@article{arxiv.1101.4884,
  title  = {4-dimensional symplectic contractions},
  author = {Marco Andreatta and Jaroslaw A. Wisniewski},
  journal= {arXiv preprint arXiv:1101.4884},
  year   = {2013}
}

Comments

27 pages

R2 v1 2026-06-21T17:16:56.315Z