“…Khan [16] also determined m n/k 1 (k, n) exactly for k = 4. As a consequence of these results, m s 1 (k, n) is determined exactly whenever s ≤ n/k and k ≤ 4 (for details see the concluding remarks in [19]). More generally, we propose the following version of Conjecture 1.3 for non-perfect matchings.…”
Section: 2mentioning
confidence: 70%
“…In particular, this implies Conjecture 1.3 for k ≤ 5. Khan [15], and independently Kühn, Osthus and Treglown [19], determined m n/k 1 (k, n) exactly for k = 3. Khan [16] also determined m n/k 1 (k, n) exactly for k = 4.…”
Abstract. A conjecture of Erdős from 1965 suggests the minimum number of edges in a kuniform hypergraph on n vertices which forces a matching of size t, where t ≤ n/k. Our main result verifies this conjecture asymptotically, for all t < 0.48n/k. This gives an approximate answer to a question of Huang, Loh and Sudakov, who proved the conjecture for t ≤ n/3k2 . As a consequence of our result, we extend bounds of Bollobás, Daykin and Erdős by asymptotically determining the minimum vertex degree which forces a matching of size t < 0.48n/(k − 1) in a k-uniform hypergraph on n vertices. We also obtain further results on d-degrees which force large matchings. In addition we improve bounds of Markström and Ruciński on the minimum ddegree which forces a perfect matching in a k-uniform hypergraph on n vertices. Our approach is to inductively prove fractional versions of the above results and then translate these into integer versions.
“…Khan [16] also determined m n/k 1 (k, n) exactly for k = 4. As a consequence of these results, m s 1 (k, n) is determined exactly whenever s ≤ n/k and k ≤ 4 (for details see the concluding remarks in [19]). More generally, we propose the following version of Conjecture 1.3 for non-perfect matchings.…”
Section: 2mentioning
confidence: 70%
“…In particular, this implies Conjecture 1.3 for k ≤ 5. Khan [15], and independently Kühn, Osthus and Treglown [19], determined m n/k 1 (k, n) exactly for k = 3. Khan [16] also determined m n/k 1 (k, n) exactly for k = 4.…”
Abstract. A conjecture of Erdős from 1965 suggests the minimum number of edges in a kuniform hypergraph on n vertices which forces a matching of size t, where t ≤ n/k. Our main result verifies this conjecture asymptotically, for all t < 0.48n/k. This gives an approximate answer to a question of Huang, Loh and Sudakov, who proved the conjecture for t ≤ n/3k2 . As a consequence of our result, we extend bounds of Bollobás, Daykin and Erdős by asymptotically determining the minimum vertex degree which forces a matching of size t < 0.48n/(k − 1) in a k-uniform hypergraph on n vertices. We also obtain further results on d-degrees which force large matchings. In addition we improve bounds of Markström and Ruciński on the minimum ddegree which forces a perfect matching in a k-uniform hypergraph on n vertices. Our approach is to inductively prove fractional versions of the above results and then translate these into integer versions.
“…In particular, in recent years there has been much study of the case of a perfect matching, see e.g. [1,2,6,11,14,16,17,18,23,26,28,29,35,36]. For perfect Hpackings other than a perfect matching, results are much more sparse.…”
Abstract. Let G and H be k-graphs (k-uniform hypergraphs); then a perfect H-packing in G is a collection of vertex-disjoint copies of H in G which together cover every vertex of G. For any fixed H let δ(H, n) be the minimum δ such that any k-graph G on n vertices with minimum codegree δ(G) ≥ δ contains a perfect H-packing. The problem of determining δ(H, n) has been widely studied for graphs (i.e. 2-graphs), but little is known for k ≥ 3. Here we determine the asymptotic value of δ(H, n) for all complete k-partite k-graphs H, as well as a wide class of other k-partite k-graphs. In particular, these results provide an asymptotic solution to a question of Rödl and Ruciński on the value of δ(H, n) when H is a loose cycle. We also determine asymptotically the codegree threshold needed to guarantee an H-packing covering all but a constant number of vertices of G for any complete k-partite k-graph H.
“…For 3‐graphs, Kühn et al. proved the following result. Theorem There exists a positive integer n 0 such that if H is a 3‐graph of order , m is an integer with , and , then .…”
For a hypergraph H, let δ1false(Hfalse) denote the minimum vertex degree in H. Kühn, Osthus, and Treglown proved that, for any sufficiently large integer n with n≡0(mod3), if H is a 3‐uniform hypergraph with order n and δ1false(Hfalse)>0ptn−12−0pt2n/32 then H has a perfect matching, and this bound on δ1false(Hfalse) is best possible. In this article, we show that under the same conditions, H contains at least ⌈(2n+3)/9⌉ pairwise disjoint perfect matchings, and this bound is sharp.
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