English

Vertex-minor universality of a random graph

Combinatorics 2026-05-06 v3

Abstract

Given a graph GG and a vertex vV(G)v\in V(G), a local complementation at vv on GG is an operation that replaces the induced graph on the neighborhood of vv by its complement. A graph HH is a vertex-minor if HH can be obtained from GG by a sequence of vertex deletions and local complementation. A graph is said to be kk-vertex-minor universal if it contains every kk-vertex graph on any kk-subset of vertices as a vertex minor. Previously, Ascoli--Fredrickson--Fredrickson--McFarland--Post proved that with high probability G(n,1/2)G(n,1/2) is Ω(n)\Omega(\sqrt{n})-vertex-minor universal. Furthermore, they conjectured that with high probability G(n,p)G(n,p) and G(n,1p)G(n,1-p) are Ω(pn)\Omega(p\sqrt{n})-vertex-minor universal for all ω(1/n)p1/2\omega(1/\sqrt{n})\le p\le 1/2. In this short note, we confirm this conjecture up to an extra logarithm factor and show that this is true with probability 12Ω(p2n)1-2^{-\Omega(p^2n)} if Ω(logn/n)p1/2\Omega(\log n/\sqrt{n})\le p\le 1/2. Together with a complementary result which applies to the regime where 1/npn1/31/\sqrt{n}\le p\le n^{-1/3} produced by an internal model at OpenAI, the conjecture is fully confirmed.

Keywords

Cite

@article{arxiv.2603.13600,
  title  = {Vertex-minor universality of a random graph},
  author = {Ting-Wei Chao and Zixuan Xu},
  journal= {arXiv preprint arXiv:2603.13600},
  year   = {2026}
}

Comments

12 pages. v3, included a complementary result generated by an internal model at OpenAI

R2 v1 2026-07-01T11:19:29.144Z