A Concrete Variant of the Twistor Theorem
Laura Fredrickson, Max Zimet
TL;DR
The paper introduces a concrete variant of the Hitchin–Karlhede–Lindström–Roček twistor theorem by starting from a real manifold $\mathcal{M}$ equipped with a $\mathbb{C}^\times$-family of holomorphic symplectic forms $\varpi(\zeta)$ of the shape $\varpi(\zeta) = - \frac{i}{2\zeta} \omega_+ + \omega_3 - \frac{i}{2} \zeta \omega_-$ with $\omega_- = \bar{\omega}_+$ and $\bar{\omega}_3 = \omega_3$, where $\omega_+$ is holomorphic. The main result proves the existence of a pseudo-hyper-Kähler structure on $\mathcal{M}$ (via a direct real-manifold argument) and shows that if $\varpi(\zeta)$ arises from a pseudo-hyper-Kähler structure, the reconstruction recovers the original metric and complex structures. This yields a more direct and practical route to HK geometries without constructing the twistor space from scratch, and clarifies the role of the $\kappa$-map and the normal-bundle condition in the HKLR framework. The work also connects with Gaiotto–Moore–Neitzke’s program for translating enumerative/semi-flat data into explicit hyper-Kähler metrics near semi-flat limits.
Abstract
In this note, we prove a concrete variant of the twistor theorem of Hitchin--Karlhede--Lindström--Roček which applies when one already has the real manifold on which one wishes to construct a hyper-Kähler structure, and so one does not need to construct it as a parameter space of twistor lines.
