FPT under feedback edge set parameterization
Determine whether the s-Club Cluster Edge Deletion problem is fixed-parameter tractable when parameterized by the feedback edge set number of the input graph; namely, decide if there exists an algorithm running in time f(fe(G))·n^{O(1)} for arbitrary s ≥ 1.
References
It is also an interesting open question whether the problem parameterized by the feedback vertex set, modular width or feedback edge set admit FPT algorithm.
— Parameterized Complexity of s-Club Cluster Edge Deletion
(2510.07065 - Gaikwad, 8 Oct 2025) in Conclusion and Open Problems