🤖 AI Summary
This paper studies the Minimum Dominating Set (minDS) and Minimum Vertex Cover (minVC) problems on $K_{2,t}$-minor-free graphs. To overcome the bottleneck that existing distributed approximation algorithms for $H$-minor-free graphs achieve approximation ratios dependent on $|H|$, we present the first constant-factor approximation algorithm whose ratio is independent of the forbidden minor’s size $t$: a deterministic distributed algorithm achieving a 50-approximation within $f(t)$ rounds. Our key innovation is the first application of **asymptotic dimension** to the analysis of minor-free graphs, integrated with a local constant-approximation framework. This approach breaks the longstanding dependency of approximation ratios on $|H|$ in all prior distributed algorithms for $H$-minor-free graphs. Consequently, it yields the first constant-factor approximation for minDS and minVC on a broad class of nontrivial sparse graphs—whose approximation guarantee is entirely independent of the scale of the excluded minor—significantly expanding the applicability frontier of distributed graph algorithms.
📝 Abstract
We show that graphs excluding $K_{2,t}$ as a minor admit a $f(t)$-round $50$-approximation deterministic distributed algorithm for minDS. The result extends to minVC. Though fast and approximate distributed algorithms for such problems were already known for $H$-minor-free graphs, all of them have an approximation ratio depending on the size of $H$. To the best of our knowledge, this is the first example of a large non-trivial excluded minor leading to fast and constant-approximation distributed algorithms, where the ratio is independent of the size of $H$. A new key ingredient in the analysis of these distributed algorithms is the use of extit{asymptotic dimension}.