{ "id": "2110.12424", "version": "v2", "published": "2021-10-24T12:22:07.000Z", "updated": "2022-08-18T11:18:17.000Z", "title": "A Note on Minimum Degree Condition for Hamiltonian $(a,b)$-Cycles in Hypergraphs", "authors": [ "Jian Wang" ], "categories": [ "math.CO" ], "abstract": "Let $k,a,b$ be positive integers with $a+b=k$. A $k$-uniform hypergraph is called an $(a,b)$-cycle if there is a partition $(A_0,B_0,A_1,B_1,\\ldots,A_{t-1},B_{t-1})$ of the vertex set with $|A_i|=a$, $|B_i|=b$ such that $A_i\\cup B_i$ and $B_i\\cup A_{i+1}$ (subscripts module $t$) are edges for all $i=0,1,\\ldots,t-1$. Let $\\mathcal{H}$ be a $k$-uniform $n$-vertex hypergraph with $n\\geq 5k$ and $n$ divisible by $k$. By applying the concentration inequality for intersections of a uniform hypergraph with a random matching developed by Frankl and Kupavskii, we show that if there exists $\\alpha\\in (0,1)$ such that $\\delta_a(\\mathcal{H})\\geq (\\alpha +o(1))\\binom{n-a}{b}$ and $\\delta_b(\\mathcal{H})\\geq (1-\\alpha +o(1))\\binom{n-b}{a}$, then $\\mathcal{H}$ contains a Hamilton $(a,b)$-cycle. As a corollary, we prove that if $\\delta_{\\ell}(\\mathcal{H})\\geq (1/2 +o(1))\\binom{n-\\ell}{k-\\ell}$ for some $\\ell \\geq k/2$, then $\\mathcal{H}$ contains a Hamilton $(k-\\ell,\\ell)$-cycle and this is asymptotically best possible.", "revisions": [ { "version": "v2", "updated": "2022-08-18T11:18:17.000Z" } ], "analyses": { "keywords": [ "minimum degree condition", "hamiltonian", "uniform hypergraph", "vertex set", "subscripts module" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }