Highly connected monochromatic subgraphs

نویسندگان

  • Béla Bollobás
  • András Gyárfás
چکیده

We conjecture that for n> 4(k−1) every 2-coloring of the edges of the complete graphKn contains a k-connectedmonochromatic subgraph with at least n − 2(k − 1) vertices. This conjecture, if true, is best possible. Here we prove it for k = 2, and show how to reduce it to the case n< 7k − 6. We prove the following result as well: for n> 16k every 2-colored Kn contains a k-connected monochromatic subgraph with at least n− 12k vertices. © 2007 Elsevier B.V. All rights reserved.

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

Note on Highly Connected Monochromatic Subgraphs in 2-Colored Complete Graphs

In this note, we improve upon some recent results concerning the existence of large monochromatic, highly connected subgraphs in a 2-coloring of a complete graph. In particular, we show that if n ≥ 6.5(k − 1), then in any 2-coloring of the edges of Kn, there exists a monochromatic k-connected subgraph of order at least n−2(k−1). Our result improves upon several recent results by a variety of au...

متن کامل

One-sided coverings of colored complete bipartite graphs

Assume that the edges of a complete bipartite graph K(A,B) are colored with r colors. In this paper we study coverings of B by vertex disjoint monochromatic cycles, connected matchings, and connected subgraphs. These problems occur in several applications.

متن کامل

Colourings of cubic graphs inducing isomorphic monochromatic subgraphs

A k–bisection of a bridgeless cubic graph G is a 2–colouring of its vertex set such that the colour classes have the same cardinality and all connected components in the two subgraphs induced by the colour classes (monochromatic components in what follows) have order at most k. Ban and Linial conjectured that every bridgeless cubic graph admits a 2–bisection except for the Petersen graph. A sim...

متن کامل

Highly Symmetric Subgraphs of Hypercubes

Two questions are considered, namely (i) How many colors are needed for a coloring of the n-cube without monochromatic quadrangles or hexagons? We show that four colors suffice and thereby settle a problem of Erdos. (ii) Which vertex-transitive induced subgraphs does a hypercube have? An interesting graph has come up in this context: If we delete a Hamming code from the 7-cube, the resulting gr...

متن کامل

Highly connected monochromatic subgraphs of multicolored graphs

We consider the following question of Bollobás: given an r-colouring of E(Kn), how large a k-connected subgraph can we find using at most s colours? We provide a partial solution to this problem when s = 1 (and n is not too small), showing that when r = 2 the answer is n−2k+2, when r = 3 the answer is ⌊n−k 2 ⌋+1 or ⌈n−k 2 ⌉ + 1, and when r − 1 is a prime power then the answer lies between n r−1...

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:
  • Discrete Mathematics

دوره 308  شماره 

صفحات  -

تاریخ انتشار 2008