## Abstract We characterize all pairs of connected graphs {__X__, __Y__} such that each 3βconnected {__X__, __Y__}βfree graph is pancyclic. In particular, we show that if each of the graphs in such a pair {__X__, __Y__} has at least four vertices, then one of them is the claw __K__~1,3~, while the
Pancyclic subgraphs of random graphs
β Scribed by Choongbum Lee; Wojciech Samotij
- Publisher
- John Wiley and Sons
- Year
- 2011
- Tongue
- English
- Weight
- 249 KB
- Volume
- 71
- Category
- Article
- ISSN
- 0364-9024
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β¦ Synopsis
Abstract
An nβvertex graph is called pancyclic if it contains a cycle of length t for all 3β€tβ€n. In this article, we study pancyclicity of random graphs in the context of resilience, and prove that if p>n^β1/2^, then the random graph G(n, p) a.a.s. satisfies the following property: Every Hamiltonian subgraph of G(n, p) with more than edges is pancyclic. This result is best possible in two ways. First, the range of p is asymptotically tight; second, the proportion of edges cannot be reduced. Our theorem extends a classical theorem of Bondy, and is closely related to a recent work of Krivelevich et al. The proof uses a recent result of Schacht (also independently obtained by Conlon and Gowers). Β© 2011 Wiley Periodicals, Inc.
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