English

Linear dependence between hereditary quasirandomness conditions

Combinatorics 2018-11-28 v2

Abstract

Answering a question of Simonovits and S\' os, Conlon, Fox, and Sudakov proved that for any nonempty graph HH, and any ε>0\varepsilon>0, there exists δ>0\delta>0 polynomial in ε\varepsilon, such that if GG is an nn-vertex graph with the property that every UV(G)U\subseteq V(G) contains pe(H)Uv(H)±δnv(H)p^{e(H)}|U|^{v(H)}\pm\delta n^{v(H)} labeled copies of HH, then GG is (p,ε)(p,\varepsilon)-quasirandom in the sense that every subset UGU\subseteq G contains 12pU2±εn2\frac{1}{2}p|U|^{2}\pm\varepsilon n^{2} edges. They conjectured that δ\delta may be taken to be linear in ε\varepsilon and proved this in the case that HH is a complete graph. We study a labelled version of this quasirandomness property proposed by Reiher and Schacht. Let HH be any nonempty graph on rr vertices v1,,vrv_{1},\ldots,v_{r}, and ε>0\varepsilon>0. We show that there exists δ=δ(ε)>0\delta=\delta(\varepsilon)>0 linear in ε\varepsilon, such that if GG is an nn-vertex graph with the property that every sequence of rr subsets U1,,UrV(G)U_{1},\ldots,U_{r}\subseteq V(G), the number of copies of HH with each viv_{i} in UiU_{i} is pe(H)Ui±δnv(H)p^{e(H)}\prod|U_{i}|\pm\delta n^{v(H)}, then GG is (p,ε)(p,\varepsilon)-quasirandom.

Keywords

Cite

@article{arxiv.1707.05396,
  title  = {Linear dependence between hereditary quasirandomness conditions},
  author = {Xiaoyu He},
  journal= {arXiv preprint arXiv:1707.05396},
  year   = {2018}
}
R2 v1 2026-06-22T20:49:40.368Z