The growth rate of multicolor Ramsey numbers of 3-graphs

TL;DR

This paper studies how the Ramsey numbers of 3-uniform hypergraphs grow with the number of colors.

Contribution

The paper determines the tower height of Ramsey numbers for 3-uniform hypergraphs as a function of the number of colors.

Findings

Ramsey numbers for 3-uniform hypergraphs can grow polynomially, exponentially, or double exponentially.

The tower height of r(G; q) is characterized for fixed 3-uniform hypergraphs G.

This resolves a question posed by Axenovich, Gyárfás, Liu, and Mubayi.

Abstract

The q-color Ramsey number of a k-uniform hypergraph G,  denoted r(G; q), is the minimum integer N such that any coloring of the edges of the complete k-uniform hypergraph on N vertices contains a monochromatic copy of G. The study of these numbers is one of the most central topics in combinatorics. One natural question, which for triangles goes back to the work of Schur in 1916, is to determine the behavior of r(G; q) for fixed G and q tending to infinity. In this paper, we study this problem for 3-uniform hypergraphs and determine the tower height of r(G; q) as a function of q. More precisely, given a hypergraph G, we determine when r(G; q) behaves polynomially, exponentially or double exponentially in q. This answers a question of Axenovich, Gyárfás, Liu and Mubayi.

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