English

Collapsing geometry of hyperk\"ahler 4-manifolds and applications

Differential Geometry 2023-01-02 v2 Mathematical Physics Analysis of PDEs math.MP

Abstract

We investigate the collapsing geometry of hyperk\"ahler 4-manifolds. As applications we prove two well-known conjectures in the field. (1) Any collapsed limit of unit-diameter hyperk\"ahler metrics on the K3 manifold is isometric to one of the following: the quotient of a flat 3-torus by an involution, a singular special K\"ahler metric on the 2-sphere, or the unit interval. (2) Any complete hyperk\"ahler 4-manifold with finite energy (i.e., gravitational instanton) is asymptotic to a model end at infinity.

Keywords

Cite

@article{arxiv.2108.12991,
  title  = {Collapsing geometry of hyperk\"ahler 4-manifolds and applications},
  author = {Song Sun and Ruobing Zhang},
  journal= {arXiv preprint arXiv:2108.12991},
  year   = {2023}
}

Comments

A conjecture on the L2-curvature energy was added in Section 7.3. To appear in Acta Mathematica