English

Random embeddings of bounded degree trees with optimal spread

Combinatorics 2024-09-11 v1

Abstract

A seminal result of Koml\'os, S\'ark\"ozy, and Szemer\'edi states that any n-vertex graph G with minimum degree at least (1/2 + {\alpha})n contains every n-vertex tree T of bounded degree. Recently, Pham, Sah, Sawhney, and Simkin extended this result to show that such graphs G in fact support an optimally spread distribution on copies of a given T, which implies, using the recent breakthroughs on the Kahn-Kalai conjecture, the robustness result that T is a subgraph of sparse random subgraphs of G as well. Pham, Sah, Sawhney, and Simkin construct their optimally spread distribution by following closely the original proof of the Koml\'os-S\'ark\"ozy-Szemer\'edi theorem which uses the blow-up lemma and the Szemer\'edi regularity lemma. We give an alternative, regularity-free construction that instead uses the Koml\'os-S\'ark\"ozy-Szemer\'edi theorem (which has a regularity-free proof due to Kathapurkar and Montgomery) as a black-box. Our proof is based on the simple and general insight that, if G has linear minimum degree, almost all constant sized subgraphs of G inherit the same minimum degree condition that G has.

Keywords

Cite

@article{arxiv.2409.06640,
  title  = {Random embeddings of bounded degree trees with optimal spread},
  author = {Paul Bastide and Clément Legrand-Duchesne and Alp Müyesser},
  journal= {arXiv preprint arXiv:2409.06640},
  year   = {2024}
}

Comments

12 pages

R2 v1 2026-06-28T18:40:08.880Z