Excluding a near-clique and a near-anticlique

نویسندگان

  • Maria Chudnovsky
  • Sergey Norin
  • Bruce Reed
  • Paul Seymour
چکیده

Ramsey’s theorem says that for every clique H1 and for every graph H2 with no edges, all graphs containing neither of H1, H2 as induced subgraphs have bounded size. What if, instead, we exclude a graph H1 with a vertex whose deletion gives a clique, and the complement H2 of another such graph? This no longer implies bounded size, but it implies tightly restricted structure that we describe. There are also several related subproblems (what if we exclude a star and the complement of a star? what if we exclude a star and a clique? and so on) and we answer a selection of these.

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

Is Ramsey's Theorem omega-automatic?

We study the existence of infinite cliques in ω-automatic (hyper-)graphs. It turns out that the situation is much nicer than in general uncountable graphs, but not as nice as for automatic graphs. More specifically, we show that every uncountable ω-automatic graph contains an uncountable co-context-free clique or anticlique, but not necessarily a context-free (let alone regular) clique or antic...

متن کامل

Is Ramsey's Theorem Ω-automatic?

We study the existence of infinite cliques in ω-automatic (hyper-)graphs. It turns out that the situation is much nicer than in general uncountable graphs, but not as nice as for automatic graphs. More specifically, we show that every uncountable ω-automatic graph contains an uncountable co-context-free clique or anticlique, but not necessarily a context-free (let alone regular) clique or antic...

متن کامل

Helly theorems for 3-Steiner and 3-monophonic convexity in graphs

A family C of sets has the Helly property if any subfamily C′, whose elements are pairwise intersecting, has non-empty intersection. Suppose C is a non-empty family of subsets of a finite set V . The Helly number h(C) of C is the smallest positive integer n such that every subfamily C′ of C with |C′| ≥ n and which intersects n-wise has non-empty intersection. In this paper we consider the famil...

متن کامل

A Neural Network Model for Finding a Near-Maximum Clique

A parallel algorithm based on the neural network model for finding a near-maximum clique is presented in this paper. A maximum clique of a graph G is a maximum complete subgraph of G where any two vertices are adjacent. The problem of finding a maximum clique is NP-complete. The parallel algorithm requires n processing elements for an n-vertex graph problem. The algorithm is verified by solving...

متن کامل

A Novel Approach to Finding Near-Cliques: The Triangle-Densest Subgraph Problem

Many graph mining applications rely on detecting subgraphs which are large near-cliques. There exists a dichotomy between the results in the existing work related to this problem: on the one hand formulations that are geared towards finding large near-cliques are NP-hard and frequently inapproximable due to connections with the Maximum Clique problem. On the other hand, the densest subgraph pro...

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:

دوره   شماره 

صفحات  -

تاریخ انتشار 2012