English

On fractional triangle decompositions of random graphs

Combinatorics 2025-11-21 v1

Abstract

We prove that with high probability G(n,p)G(n,p) with pn4/11+o(1)p \geq n^{-4/11 + o(1)} admits a fractional triangle decomposition (FTD), i.e., a nonnegative weighting of its triangles such that for each edge, the total weight of the triangles containing it equals one. This improves on the state of the art, due to Delcourt, Kelly, and Postle, that pn1/3+o(1)p \geq n^{-1/3+o(1)} suffices. The proof is algorithmic: Given GG(n,p)G \sim G(n,p), we first construct an approximate FTD by taking a uniform weighting of the triangles. We then use specialized gadgets to iteratively shift weights and obtain successively better approximations of an FTD.

Keywords

Cite

@article{arxiv.2511.15877,
  title  = {On fractional triangle decompositions of random graphs},
  author = {Ghaura Mahabaduge and Michael Simkin},
  journal= {arXiv preprint arXiv:2511.15877},
  year   = {2025}
}

Comments

31 pages, 9 figures