If G is a block, then a vertex u of G is called critical if Gu is not a block. In this article, relationships between the localization of critical vertices and the localization of vertices of relatively small degrees (especially, of degree two) are studied. A block is called semicritical if a) each
Induced subgraphs of prescribed size
β Scribed by Noga Alon; Michael Krivelevich; Benny Sudakov
- Publisher
- John Wiley and Sons
- Year
- 2003
- Tongue
- English
- Weight
- 127 KB
- Volume
- 43
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
β¦ Synopsis
Abstract
A subgraph of a graph G is called trivial if it is either a clique or an independent set. Let q(G) denote the maximum number of vertices in a trivial subgraph of G. Motivated by an open problem of ErdΕs and McKay we show that every graph G on n vertices for which q(G)β€ C log n contains an induced subgraph with exactly y edges, for every y between 0 and n^Ξ΄ (C)^. Our methods enable us also to show that under much weaker assumption, i.e., q(G) β€ n/14, G still must contain an induced subgraph with exactly y edges, for every y between 0 and $e^{\Omega} (\sqrt { \log, n})$. Β© 2003 Wiley Periodicals, Inc. J Graph Theory 43: 239β251, 2003
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