We prove the conjecture of Gould and Jacobson that a connected S(K1,J free graph has a vertex pancyclic square. Since .S(K1,J is not vertex pancyclic, this result is best possible. ## Our notation generally follows that used in [l] . A graph G is Hamilroniun if it contains a cycle through all its
Forbidden subgraphs and hamiitonian properties in the square of a connected graph
β Scribed by Ronald J. Gould; Michael S. Jacobson
- Publisher
- John Wiley and Sons
- Year
- 1984
- Tongue
- English
- Weight
- 331 KB
- Volume
- 8
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
β¦ Synopsis
Various Hamiltonian-like properties are investigated in the squares of connected graphs free of some set of forbidden subgraphs. The star K,+ the subdivision graph of &, and the subdivision graph of K1,3 minus an endvertex play central roles. In particular, we show that connected graphs free of the subdivision graph of K,,3 minus an endvertex have vertex pancyclic squares.
In this article, all graphs are finite, undirected, without loops or multiple edges. Terms not defined here can be found in [I]. If U is a nonempty subset of the vertex set V ( G ) of a graph G . then the subgraph (U) of G induced by U is the graph with vertex set U and whose edge set consists of those edges of G incident with two elements of U. A graph is Harniltonian if it contains a cycle through all its vertices. A graph is vertex pancyclic if each of its vertices lies on a cycle of length e, for each e, 3 e 6 IV(G)l. The square of a graph G , denoted GZ, is that graph obtained from G by inserting an edge between any two vertices at distance 2 apart in
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