Cover k-Uniform Hypergraphs by Monochromatic Loose Paths

نویسندگان

  • Changhong Lu
  • Rui Mao
  • Bing Wang
  • Ping Zhang
چکیده

A conjecture of Gyárfás and Sárközy says that in every 2-coloring of the edges of the complete k-uniform hypergraph Kk n, there are two disjoint monochromatic loose paths of distinct colors such that they cover all but at most k − 2 vertices. Recently, the authors affirmed the conjecture. In the note we show that for every 2-coloring of Kk n, one can find two monochromatic paths of distinct colors to cover all vertices of Kk n such that they share at most k − 2 vertices. Omidi and Shahsiah conjectured that R(Pk t ,Pk t ) = t(k − 1) + b t+1 2 c holds for k > 3 and they affirmed the conjecture for k = 3 or k > 8. We show that if the conjecture is true, then k−2 is best possible for our result.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Monochromatic Path and Cycle Partitions in Hypergraphs

Here we address the problem to partition edge colored hypergraphs by monochromatic paths and cycles generalizing a well-known similar problem for graphs. We show that r-colored r-uniform complete hypergraphs can be partitioned into monochromatic Berge-paths of distinct colors. Also, apart from 2k − 5 vertices, 2-colored k-uniform hypergraphs can be partitioned into two monochromatic loose paths...

متن کامل

Monochromatic Loose-cycle Partitions in Hypergraphs

In this paper we study the monochromatic loose-cycle partition problem for non-complete hypergraphs. Our main result is that in any r-coloring of a k-uniform hypergraph with independence number α there is a partition of the vertex set into monochromatic loose cycles such that their number depends only on r, k and α. We also give an extension of the following result of Pósa to hypergraphs: the v...

متن کامل

Turán Numbers for Forests of Paths in Hypergraphs

The Turán number of an r-uniform hypergraph H is the maximum number of edges in any r-graph on n vertices which does not contain H as a subgraph. Let P denote the family of r-uniform loose paths on edges, F(k, l) denote the family of hypergraphs consisting of k disjoint paths from P , and L (r) denote an r-uniform linear path on edges. We determine precisely exr(n;F(k, l)) and exr(n; k · L ), a...

متن کامل

The Ramsey Number of Loose Paths in 3-Uniform Hypergraphs

Recently, asymptotic values of 2-color Ramsey numbers for loose cycles and also loose paths were determined. Here we determine the 2-color Ramsey number of 3-uniform loose paths when one of the paths is significantly larger than the other: for every n > ⌊ 5m 4 ⌋ , we show that R(P n,P m) = 2n + ⌊m + 1 2 ⌋ .

متن کامل

The Ramsey Number of Loose Triangles and Quadrangles in Hypergraphs

Asymptotic values of hypergraph Ramsey numbers for loose cycles (and paths) were determined recently. Here we determine some of them exactly, for example the 2-color hypergraph Ramsey number of a k-uniform loose 3-cycle or 4-cycle: R(Ck 3 , Ck 3 ) = 3k − 2 and R(Ck 4 , Ck 4 ) = 4k − 3 (for k > 3). For more than 3 colors we could prove only that R(C3 3 , C3 3 , C3 3) = 8. Nevertheless, the r-col...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • Electr. J. Comb.

دوره 24  شماره 

صفحات  -

تاریخ انتشار 2017