Abstract
We prove that a k-connected graph (k>2) is Hamiltonian if it is not contractible to one of a specified collection of graphs of order 2k+1. The theorem generalizes a previous result of the authors. The proof partly parallels that of the following, less general, result of Chvátal and Erdös: A k-connected graph containing no independent set of more than k points (k>2) is Hamiltonian (*). Also stated in terms of contractibility are sufficient conditions for graphs to be traceable, Hamiltonian connected or 1-Hamiltonian, respectively. Conditions analogous to (*) guaranteeing the same properties were found by Chvátal and Erdös and by Lesniak. For traceable and 1-Hamiltonian graphs the contraction theorems sharpen the corresponding analogues of (*), while equivalence is conjectured for Hamiltonian connected graphs.
Original language | English |
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Pages (from-to) | 61-67 |
Journal | Discrete mathematics |
Volume | 34 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1981 |
Keywords
- IR-68715