English

On some graph densities in locally dense graphs

Combinatorics 2019-08-12 v2

Abstract

The Kohayakawa-Nagle-R\"odl-Schacht conjecture roughly states that every sufficiently large locally dd-dense graph GG on nn vertices must contain at least (1o(1))dE(H)nV(H)(1-o(1))d^{|E(H)|}n^{|V(H)|} copies of a fixed graph HH. Despite its important connections to both quasirandomness and Ramsey theory, there are very few examples known to satisfy the conjecture. We provide various new classes of graphs that satisfy the conjecture. Firstly, we prove that adding an edge to a cycle or a tree produces graphs that satisfy the conjecture. Secondly, we prove that a class of graphs obtained by gluing complete multipartite graphs in a tree-like way satisfies the conjecture. We also prove an analogous result with odd cycles replacing complete multipartite graphs.

Keywords

Cite

@article{arxiv.1707.02916,
  title  = {On some graph densities in locally dense graphs},
  author = {Joonkyung Lee},
  journal= {arXiv preprint arXiv:1707.02916},
  year   = {2019}
}

Comments

21 pages, new results added to the previous version

R2 v1 2026-06-22T20:42:37.056Z