On a Ramsey--Turán variant of Roth's theorem

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Bucić, Matija, Christoph, Micha, Kim, Jaehoon, Lee, Hyunwoo, Sivashankar, Varun
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866916871398227968
author Bucić, Matija
Christoph, Micha
Kim, Jaehoon
Lee, Hyunwoo
Sivashankar, Varun
author_facet Bucić, Matija
Christoph, Micha
Kim, Jaehoon
Lee, Hyunwoo
Sivashankar, Varun
contents A classical theorem of Roth states that the maximum size of a solution-free set of a homogeneous linear equation $\mathcal{L}$ in $\mathbb{F}_p$ is $o(p)$ if and only if the sum of the coefficients of $\mathcal{L}$ is $0$. In this paper, we prove a Ramsey--Turán variant of Roth's theorem, with respect to a natural notion of ``structured'' sets introduced by Erdős and Sárközy in the 1970's. Namely, we show that the following statements are equivalent: $(a)$ Every solution-free set $A$ of $\mathcal{L}$ in $\mathbb{F}_p$ with $α(\mathrm{Cay}_{\mathbb{F}_p}(A)) = o(p)$ has size $o(p)$. $(b)$ There exists a non-empty \emph{subset} of coefficients of $\mathcal{L}$ with zero sum.
format Preprint
id arxiv_https___arxiv_org_abs_2507_22831
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle On a Ramsey--Turán variant of Roth's theorem
Bucić, Matija
Christoph, Micha
Kim, Jaehoon
Lee, Hyunwoo
Sivashankar, Varun
Combinatorics
A classical theorem of Roth states that the maximum size of a solution-free set of a homogeneous linear equation $\mathcal{L}$ in $\mathbb{F}_p$ is $o(p)$ if and only if the sum of the coefficients of $\mathcal{L}$ is $0$. In this paper, we prove a Ramsey--Turán variant of Roth's theorem, with respect to a natural notion of ``structured'' sets introduced by Erdős and Sárközy in the 1970's. Namely, we show that the following statements are equivalent: $(a)$ Every solution-free set $A$ of $\mathcal{L}$ in $\mathbb{F}_p$ with $α(\mathrm{Cay}_{\mathbb{F}_p}(A)) = o(p)$ has size $o(p)$. $(b)$ There exists a non-empty \emph{subset} of coefficients of $\mathcal{L}$ with zero sum.
title On a Ramsey--Turán variant of Roth's theorem
topic Combinatorics
url https://arxiv.org/abs/2507.22831