Abstract. Given positive integers a ≤ b ≤ c, let K a,b,c be the complete 3-partite 3-uniform hypergraph with three parts of sizes a, b, c. Let H be a 3-uniform hypergraph on n vertices where n is divisible by a + b + c. We asymptotically determine the minimum vertex degree of H that guarantees a perfect K a,b,ctiling, that is, a spanning subgraph of H consisting of vertex-disjoint copies of K a,b,c . This partially answers a question of Mycroft, who proved an analogous result with respect to codegree for r-uniform hypergraphs for all r ≥ 3. Our proof uses a lattice-based absorbing method, the concept of fractional tiling, and a recent result on shadows for 3-graphs.
For k ≥ 3 and ǫ > 0, let H be a k-partite k-graph with parts V 1 , . . . , V k each of size n, where n is sufficiently large. Assume that for each i ∈ [k], every (k − 1)-set in j∈[k]\{i} V i lies in at least a i edges, andIn particular, H contains a matching of size n − 1 if each crossing (k − 1)-set lies in at least ⌈n/k⌉ edges, or each crossing (k − 1)-set lies in at least ⌊n/k⌋ edges and n ≡ 1 mod k. This special case answers a question of Rödl and Ruciński and was independently obtained by Lu, Wang, and Yu.The proof of Lu, Wang, and Yu closely follows the approach of Han [Combin. Probab. Comput. 24 (2015), 723-732] by using the absorbing method and considering an extremal case. In contrast, our result is more general and its proof is thus more involved: it uses a more complex absorbing method and deals with two extremal cases.
For k≥3 and ϵ>0, let H be a k‐partite k‐graph with parts V1,…,Vk each of size n, where n is sufficiently large. Assume that for each i∈[k], every (k−1)‐set in ∏j∈[k]\{i}Vj lies in at least ai edges, and a1≥a2≥⋯≥ak. We show that if a1,a2≥ϵn, then H contains a matching of size minfalse{n−1,∑i∈[k]aifalse}. In particular, H contains a matching of size n−1 if each crossing (k−1)‐set lies in at least ⌈n/k⌉ edges, or each crossing (k−1)‐set lies in at least ⌊n/k⌋ edges and n≡10.2emmod0.2emk. This special case answers a question of Rödl and Ruciński and was independently obtained by Lu, Wang, and Yu. The proof of Lu, Wang, and Yu closely follows the approach of Han by using the absorbing method and considering an extremal case. In contrast, our result is more general and its proof is thus more involved: it uses a more complex absorbing method and deals with two extremal cases.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.