4/3-Approximation of Graphic TSP

Abstract

We describe a $\frac{4}{3}$-approximation algorithm for the traveling salesman problem in which the distances between points are induced by graph-theoretical distances in an unweighted graph. The algorithm is based on finding a minimum cost perfect matching on the odd degree vertices of a carefully computed 2-edge-connected spanning subgraph.

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 Errors affecting the main results were later identified, and the manuscript has been withdrawn