Averages of hypergraphs and higher arity stability

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Chernikov, Artem, Towsner, Henry
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866913979853438976
author Chernikov, Artem
Towsner, Henry
author_facet Chernikov, Artem
Towsner, Henry
contents We show that $k$-ary functions giving the measure of the intersection of multi-parametric families of sets in probability spaces, e.g. $(x,y,z) \in X \times Y \times Z \mapsto μ(P_{x,y} \cap Q_{x,z} \cap R_{y,z})$, satisfy a particularly strong form of hypergraph regularity. More generally, this applies to the (integral) averages of continuous combinations of functions of smaller arity. This result is connected to higher arity stability in model theory, that we discuss in the second part of the paper. We demonstrate that all hypergraphs embedding both into the half-simplex and into $GS(\mathbb{F}_3)$, the two known sources of failure of ternary stability, do satisfy an analogous regularity lemma -- hence strong ternary stability cannot be characterized simply by excluded hypergraphs.
format Preprint
id arxiv_https___arxiv_org_abs_2508_05839
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Averages of hypergraphs and higher arity stability
Chernikov, Artem
Towsner, Henry
Combinatorics
Logic
Probability
03C45, 05C65, 05C75, 05C35, 60C05, 60A10
We show that $k$-ary functions giving the measure of the intersection of multi-parametric families of sets in probability spaces, e.g. $(x,y,z) \in X \times Y \times Z \mapsto μ(P_{x,y} \cap Q_{x,z} \cap R_{y,z})$, satisfy a particularly strong form of hypergraph regularity. More generally, this applies to the (integral) averages of continuous combinations of functions of smaller arity. This result is connected to higher arity stability in model theory, that we discuss in the second part of the paper. We demonstrate that all hypergraphs embedding both into the half-simplex and into $GS(\mathbb{F}_3)$, the two known sources of failure of ternary stability, do satisfy an analogous regularity lemma -- hence strong ternary stability cannot be characterized simply by excluded hypergraphs.
title Averages of hypergraphs and higher arity stability
topic Combinatorics
Logic
Probability
03C45, 05C65, 05C75, 05C35, 60C05, 60A10
url https://arxiv.org/abs/2508.05839