English

A concentration inequality for random combinatorial optimisation problems

Combinatorics 2024-07-18 v1 Probability

Abstract

Given a finite set SS, i.i.d. random weights {Xi}iS\{X_i\}_{i\in S}, and a family of subsets F2S\mathcal{F}\subseteq 2^S, we consider the minimum weight of an FFF\in \mathcal{F}: M(F):=minFFiFXi. M(\mathcal{F}):= \min_{F\in \mathcal{F}} \sum_{i\in F}X_i. In particular, we investigate under what conditions this random variable is sharply concentrated around its mean. We define the patchability of a family F\mathcal{F}: essentially, how expensive is it to finish an almost-complete FF (that is, FF is close to F\mathcal{F} in Hamming distance) if the edge weights are re-randomized? Combining the patchability of F\mathcal{F}, applying the Talagrand inequality to a dual problem, and a sprinkling-type argument, we prove a concentration inequality for the random variable M(F)M(\mathcal{F}).

Keywords

Cite

@article{arxiv.2407.12672,
  title  = {A concentration inequality for random combinatorial optimisation problems},
  author = {Joel Larsson Danielsson},
  journal= {arXiv preprint arXiv:2407.12672},
  year   = {2024}
}
R2 v1 2026-06-28T17:44:37.774Z