English

Separating subadditive Euclidean functionals

Probability 2015-05-22 v4 Discrete Mathematics Combinatorics

Abstract

If we are given nn random points in the hypercube [0,1]d[0,1]^d, then the minimum length of a Traveling Salesperson Tour through the points, the minimum length of a spanning tree, and the minimum length of a matching, etc., are known to be asymptotically βnd1d\beta n^{\frac{d-1}{d}} a.s., where β\beta is an absolute constant in each case. We prove separation results for these constants. In particular, concerning the constants βTSPd\beta_{\mathrm{TSP}}^d, βMSTd\beta_{\mathrm{MST}}^d, βMMd\beta_{\mathrm{MM}}^d, and βTFd\beta_{\mathrm{TF}}^d from the asymptotic formulas for the minimum length TSP, spanning tree, matching, and 2-factor, respectively, we prove that βMSTd<βTSPd\beta_{\mathrm{MST}}^d<\beta_{\mathrm{TSP}}^d, 2βMMd<βTSPd2\beta_{\mathrm{MM}}^d<\beta_{\mathrm{TSP}}^d, and βTFd<βTSPd\beta_{\mathrm{TF}}^d<\beta_{\mathrm{TSP}}^d for all d2d\geq 2. We also asymptotically separate the TSP from its linear programming relaxation in this setting. Our results have some computational relevance, showing that a certain natural class of simple algorithms cannot solve the random Euclidean TSP efficiently.

Cite

@article{arxiv.1501.01944,
  title  = {Separating subadditive Euclidean functionals},
  author = {Alan Frieze and Wesley Pegden},
  journal= {arXiv preprint arXiv:1501.01944},
  year   = {2015}
}

Comments

32 pages, 5 figures. Branch and bound theorem is now unconditional

R2 v1 2026-06-22T07:55:29.219Z