An Ore-type theorem for $[3]$-graphs

TL;DR

This paper extends Ore's classical Hamiltonian cycle theorem to 3-uniform hypergraphs, establishing conditions based on the degree sum in the shadow graph that guarantee the existence of Hamiltonian Berge cycles.

Contribution

It proves an Ore-type theorem for 3-uniform hypergraphs, linking degree sums in the shadow graph to Hamiltonian Berge cycles, and proposes a conjecture for optimal bounds.

Findings

Existence of a constant d_0 ensuring Hamiltonian Berge cycles under degree sum conditions

Extension of Ore's theorem from graphs to 3-uniform hypergraphs

Conjecture that the bound d_0=1 is sufficient for all n ≥ 6

Abstract

Ore's Theorem states that if $G$ is an $n$-vertex graph and every pair of non-adjacent vertices has degree sum at least $n$, then $G$ is Hamiltonian. A $[3]$-graph is a hypergraph in which every edge contains at most $3$ vertices. In this paper, we prove an Ore-type result on the existence of Hamiltonian Berge cycles in $[3]$-graph $\cH$, based on the degree sum of every pair of non-adjacent vertices in the $2$-shadow graph $\partial \cH$ of $\cH$. Namely, we prove that there exists a constant $d_0$ such that for all $n \geq 6$, if a $[3]$-graph $\cH$ on $n$ vertices satisfies that every pair $u,v \in V(\cH)$ of non-adjacent vertices has degree sum $d_{\partial \cH}(u) + d_{\partial \cH}(v) \geq n+d_0$, then $\cH$ contains a Hamiltonian Berge cycle. Moreover, we conjecture that $d_0=1$ suffices.