English

The sum-free process

Combinatorics 2019-12-03 v2

Abstract

SZ2nS \subseteq \mathbb{Z}_{2n} is said to be sum-free if SS has no solution to the equation a+b=ca+b=c. The sum-free process on Z2n\mathbb{Z}_{2n} starts with S:=S:=\emptyset, and iteratively inserts elements of Z2n\mathbb{Z}_{2n}, where each inserted element is chosen uniformly at random from the set of all elements that could be inserted while maintaining that SS is sum-free. We prove a lower bound (which holds with high probability) on the final size of SS, which matches a more general result of Bennett and Bohman, and also matches the order of a sharp threshold result proved by Balogh, Morris and Samotij. We also show that the set SS produced by the process has a particular non-pseudorandom property, which is in contrast with several known results about the random greedy independent set process on hypergraphs.

Keywords

Cite

@article{arxiv.1502.01644,
  title  = {The sum-free process},
  author = {Patrick Bennett},
  journal= {arXiv preprint arXiv:1502.01644},
  year   = {2019}
}

Comments

19 pages

R2 v1 2026-06-22T08:23:06.217Z