3/2-Approximation for the Forest Augmentation Problem

Abstract

We describe a $\frac{3}{2}$-approximation algorithm for the Forest Augmentation Problem (\textsf{FAP}), which is a special case of the Weighted 2-Edge-Connected Spanning Subgraph Problem (\textsf{Weighted 2-ECSS}). This significantly improves upon the previous best ratio $1.9973$, and proceeds toward the goal of a $\frac{3}{2}$-approximation algorithm for \textsf{Weighted 2-ECSS}.

This was an early and insufficiently verified attempt. Errors affecting the main results were later identified, and the manuscript has been withdrawn