Large $Y_{3,2}$-tilings in 3-uniform hypergraphs

Abstract

Let $Y_{3,2}$ be the 3-graph with two edges intersecting in two vertices. We prove that every 3-graph $H$ on $n$ vertices with at least $\max \left\{\left(\genfrac{}{}{0ex}{}{4\hat{I}\pm n}{3}\right),\left(\genfrac{}{}{0ex}{}{n}{3}\right)-\left(\genfrac{}{}{0ex}{}{n-\hat{I}\pm n}{3}\right)\right\}+o(n^3)$ edges contains a $Y_{3,2}$-tiling covering more than $4\hat{I}\pm n$ vertices, for sufficiently large $n$ and $0<\hat{I}\pm <1/4$. The bound on the number of edges is asymptotically best possible and solves a conjecture of the authors for 3-graphs that generalizes the Matching Conjecture of Erdős.

Acccepted by European Journal of Combinatorics