Tight Codegree Condition for the Existence of Loose Hamilton Cycles in 3-Graphs

In 2006, Kuhn and Osthus [J. Combin. Theory Ser. B, 96 (2006), pp. 767--821] showed that if a 3-graph $H$ on $n$ vertices has minimum codegree at least $(1/4 +o(1))n$ and $n$ is even, then $H$ has a loose Hamilton cycle. In this paper, we prove that the minimum codegree of $n/4$ suffices. The result is tight.