Anti-Ramsey Numbers of Expansions of Doubly Edge-critical Graphs in Uniform Hypergraphs

TL;DR

This paper determines the exact anti-Ramsey numbers for expansions of doubly edge-critical 2-graphs in uniform hypergraphs, extending known results from graphs to hypergraphs for large vertex sets.

Contribution

It provides the first exact values of anti-Ramsey numbers for certain hypergraph expansions of doubly edge-critical graphs, generalizing previous graph results.

Findings

Exact anti-Ramsey numbers for hypergraph expansions of doubly edge-critical graphs.

Extension of known graph anti-Ramsey results to hypergraphs.

Applicable for large vertex sets and specific parameters.

Abstract

For an $r$-graph $H$, the anti-Ramsey number ${\rm ar}(n,r,H)$ is the minimum number $c$ of colors such that for any edge-coloring of the complete $r$-graph on $n$ vertices with at least $c$ colors, there is a copy of $H$ whose edges have distinct colors. A 2-graph $F$ is doubly edge-$p$-critical if the chromatic number $\chi(F - e)\geq p$ for every edge $e$ in $F$ and there exist two edges $e_1,e_2$ in $F$ such that $\chi(F -e_1- e_2)=p-1$. The anti-Ramsey numbers of doubly edge-$p$-critical 2-graphs were determined by Jiang and Pikhurko \cite{Jiang&Pikhurko2009}, which generalized the anti-Ramsey numbers of cliques determined by Erd\H{o}s, Simonovits and S\'{o}s \cite{Erdos&Simonovits&Sos1975}. In general, few exact values of anti-Ramsey numbers of $r$-graphs are known for $r\geq 3$. Given a 2-graph $F$, the expansion $F^{(r)}$ of $F$ is an $r$-graph on $|V(F)|+(r-2)|F|$ vertices obtained from $F$ by adding $r-2$ new vertices to each edge of $F$. In this paper, we determine the exact value of ${\rm ar}(n,r,F^{(r)})$ for any doubly edge-$p$-critical 2-graph $F$ with $p>r\geq 3$ and sufficiently large $n$.