Isotopy of symplectic forms on K3 surfaces to Kähler forms
Determine whether every symplectic form on a K3 surface is isotopic, through symplectic forms, to a Kähler form. Equivalently, prove or refute the conjecture that any symplectic structure on a K3 surface is isotopic to a Kähler one.
References
It's been conjectured that any symplectic form on a K3 surface is isotopic to a K"ahler one Conjecture 4.2; however, this question remains in general completely open. See for Donaldson's proposed geometric approach to the problem.
— Homological mirror symmetry for projective K3 surfaces
(2503.05680 - Hacking et al., 7 Mar 2025) in Remark, Section 1.3 (Overview of the proof), Step (D)