Applications of the regularity lemma for uniform hypergraphs

نویسندگان

  • Vojtech Rödl
  • Jozef Skokan
چکیده

In this note we discuss several combinatorial problems that can be addressed by the Regularity Method for hypergraphs. Based on recent results of Nagle, Schacht and the authors, we give here solutions to these problems. In particular, we prove the following: Let K (k) t be the complete kuniform hypergraph on t vertices and suppose an n-vertex k-uniform hypergraph H contains only o(n) copies of K (k) t . Then one can delete o(n) edges of H to make it K (k) t -free. Similar results were recently obtained by W. T. Gowers.

برای دانلود 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

Regularity Lemma for k-uniform hypergraphs

Szemerédi’s Regularity Lemma proved to be a very powerful tool in extremal graph theory with a large number of applications. Chung [Regularity lemmas for hypergraphs and quasi-randomness, Random Structures and Algorithms 2 (1991), 241–252], Frankl and Rödl [The uniformity lemma for hypergraphs, Graphs and Combinatorics 8 (1992), 309–312, Extremal problems on set systems, Random Structures and A...

متن کامل

3-Uniform hypergraphs of bounded degree have linear Ramsey numbers

Chvátal, Rödl, Szemerédi and Trotter [1] proved that the Ramsey numbers of graphs of bounded maximum degree are linear in their order. We prove that the same holds for 3-uniform hypergraphs. The main new tool which we prove and use is an embedding lemma for 3-uniform hypergraphs of bounded maximum degree into suitable 3-uniform ‘pseudo-random’ hypergraphs. keywords: hypergraphs; regularity lemm...

متن کامل

Counting Small Cliques in 3-uniform Hypergraphs

Many applications of Szemerédi’s Regularity Lemma for graphs are based on the following counting result. If G is an s-partite graph with partition V (G) = ⋃s i=1 Vi, |Vi| = m for all i ∈ [s], and all pairs (Vi, Vj ), 1 i < j s, are -regular of density d, then G contains (1± f( ))d s 2 ms cliques Ks, provided < (d), where f( ) tends to 0 as tends to 0. Guided by the regularity lemma for 3-unifor...

متن کامل

EMBEDDINGS AND RAMSEY NUMBERS OF SPARSE k-UNIFORM HYPERGRAPHS

Chvátal, Rödl, Szemerédi and Trotter [3] proved that the Ramsey numbers of graphs of bounded maximum degree are linear in their order. In [6, 23] the same result was proved for 3-uniform hypergraphs. Here we extend this result to k-uniform hypergraphs for any integer k ≥ 3. As in the 3-uniform case, the main new tool which we prove and use is an embedding lemma for k-uniform hypergraphs of boun...

متن کامل

The hypergraph regularity method and its applications.

Szemeredi's regularity lemma asserts that every graph can be decomposed into relatively few random-like subgraphs. This random-like behavior enables one to find and enumerate subgraphs of a given isomorphism type, yielding the so-called counting lemma for graphs. The combined application of these two lemmas is known as the regularity method for graphs and has proved useful in graph theory, comb...

متن کامل

Short paths in 3-uniform quasi-random hypergraphs

Frankl and Rödl [3] proved a strong regularity lemma for 3-uniform hypergraphs, based on the concept of δ-regularity with respect to an underlying 3-partite graph. In applications of that lemma it is often important to be able to “glue” together separate pieces of the desired subhypergraph. With this goal in mind, in this paper it is proved that every pair of typical edges of the underlying gra...

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

برای دانلود 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

عنوان ژورنال:
  • Random Struct. Algorithms

دوره 28  شماره 

صفحات  -

تاریخ انتشار 2006