We improve the lower bound on the integrality ratio of the Held-Karp bound for asymmetric TSP (with triangle inequality) from 4/3 to 2.
Citation:
Moses Charikar, Michel X. Goemans, Howard Karloff, "On the Integrality Ratio for Asymmetric TSP," focs, pp.101-107, 45th Annual IEEE Symposium on Foundations of Computer Science (FOCS'04), 2004