Integrability of Higher-Dimensional Quadratic Tables
Determine whether outer contact billiards over quadratic hypersurfaces remain integrable in projective contact spaces of dimensions higher than three.
References
Is the outer contact billiard map over quadratic surfaces still integrable in higher dimensions?
— Outer Contact Billiards
(2608.19393 - Caliz et al., 19 Aug 2026) in Section 6, “Open questions,” item 5