Approximation of k-Dominating Set below exhaustive-search time

Determine whether k-Dominating Set admits a $(\log n)^{1-o(1)}$-approximation algorithm running in $n^{k-0.1}$ time, where $n$ is the number of vertices in the input graph.

Background

The paper situates its results within the broader problem of understanding the tradeoff between approximation quality and running time for parameterized covering problems. A survey by Feldmann, Karthik, Lee, and Manurangsi formulates the cited question for kk-Dominating Set: whether one can obtain an approximation factor nearly logarithmic in the graph size while saving a fixed constant from the exhaustive-search exponent kk.

The results in the paper establish near-logarithmic running-time lower bounds for parameterized Set Cover, including a lower bound under SETH against algorithms with running time O(∣Γ∣k−δ)O(|\Gamma|^{k-\delta}). However, the explicitly cited question concerns kk-Dominating Set, so it is stated as a separate unresolved question in the paper’s discussion of prior work.

References

Their Open Question 4 asks whether $k$-\textnormal{Dominating Set} admits a $(\log n){1-o(1)}$ approximation in $n{k-0.1}$ time, where $n$ denotes the number of vertices of the input graph.

— Near-Logarithmic Inapproximability of Parameterized Set Cover  (2609.19623 - Lin et al., 17 Sep 2026) in Section 1, Introduction, paragraph beginning “The goal of determining this tradeoff”