Faster Sublinear Maximal Independent Set Size

We give a sublinear-time algorithm for estimating the size of a maximal independent set in a graph using adjacency-query access with expected running time $\tilde{O}(n^{1+1\mathrm{/}3})$, improving over the previous $\tilde{O}(n^{1+1\mathrm{/}2})$ bound of Mahadabi et al. [MRTV26]. As a consequence of a reduction of [MRTV26], this also improves the running time for sublinear metric Steiner forest. We further show that a bi-criteria estimate of the $k$-center objective in general metrics can be obtained via a reduction to maximal independent set size estimation.