Factor Three Approximation for Edit Distance

We give randomized algorithms for $3$-approximate edit distance in $\widetilde{\mathcal{O}}(N^{11/6})$ time for unweighted edit distance and in $\widetilde{\mathcal{O}}(N^{40/21})$ time for arbitrary metric edit weights, where $N$ is the total input length. For non-metric costs, we prove an uncond