A note on the minimum size of Turán systems

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Liu, Xizhi, Pikhurko, Oleg
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866910809873973248
author Liu, Xizhi
Pikhurko, Oleg
author_facet Liu, Xizhi
Pikhurko, Oleg
contents For positive integers $n \ge s > r$, a \emph{Turán $(n,s,r)$-system} is an $n$-vertex $r$-graph in which every set of $s$ vertices contains at least one edge. Let $T(n,s,r)$ denote the the minimum size of a Turán $(n,s,r)$-system. Upper bounds on $T(n,s,r)$ were established by Sidorenko~\cite{Sid97} for the case $s-r = Ω(r/\ln r)$ (based on a construction of Frankl--Rödl~\cite{FR85}) and by a number of authors in the case $s-r = O(1)$. In this note, we establish upper bounds in the remaining range $O(1)<s-r = O(r/\ln r)$.
format Preprint
id arxiv_https___arxiv_org_abs_2501_15457
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle A note on the minimum size of Turán systems
Liu, Xizhi
Pikhurko, Oleg
Combinatorics
For positive integers $n \ge s > r$, a \emph{Turán $(n,s,r)$-system} is an $n$-vertex $r$-graph in which every set of $s$ vertices contains at least one edge. Let $T(n,s,r)$ denote the the minimum size of a Turán $(n,s,r)$-system. Upper bounds on $T(n,s,r)$ were established by Sidorenko~\cite{Sid97} for the case $s-r = Ω(r/\ln r)$ (based on a construction of Frankl--Rödl~\cite{FR85}) and by a number of authors in the case $s-r = O(1)$. In this note, we establish upper bounds in the remaining range $O(1)<s-r = O(r/\ln r)$.
title A note on the minimum size of Turán systems
topic Combinatorics
url https://arxiv.org/abs/2501.15457