Existence of Constant-Factor Approximation for OPS
Determine whether Optimisation Polyamorous Scheduling admits a polynomial-time constant-factor approximation algorithm that achieves a fixed approximation ratio independent of the instance size and maximum degree.
References
Although BGT can be approximated well, since it is in general not possible to combine local schedules into a global schedule for a polycule (as noted above), it is not clear whether Poly Scheduling allows an efficient constant-factor approximation.
— Polyamorous Scheduling
(2403.00465 - Gąsieniec et al., 1 Mar 2024) in Section 1.2 (Related Work)