Bauer, D., Broersma, H. J., van den Heuvel, Jan, Kahl, N. and Schmeichel, E.
(2012)
*Degree sequences and the existence of k-Factors.*
Graphs and Combinatorics, 28
(2).
pp. 149-166.
ISSN 0911-0119

## Abstract

We consider sufficient conditions for a degree sequence π to be forcibly k-factor graphical. We note that previous work on degrees and factors has focused primarily on finding conditions for a degree sequence to be potentially k-factor graphical. We first give a theorem for π to be forcibly 1-factor graphical and, more generally, forcibly graphical with deficiency at most β ≥ 0. These theorems are equal in strength to Chvátal's well-known hamiltonian theorem, i. e., the best monotone degree condition for hamiltonicity. We then give an equally strong theorem for π to be forcibly 2-factor graphical. Unfortunately, the number of nonredundant conditions that must be checked increases significantly in moving from k = 1 to k = 2, and we conjecture that the number of nonredundant conditions in a best monotone theorem for a k-factor will increase superpolynomially in k. This suggests the desirability of finding a theorem for π to be forcibly k-factor graphical whose algorithmic complexity grows more slowly. In the final section, we present such a theorem for any k ≥ 2, based on Tutte's well-known factor theorem. While this theorem is not best monotone, we show that it is nevertheless tight in a precise way, and give examples illustrating this tightness.

Item Type: | Article |
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Official URL: | http://www.springer.com/new+%26+forthcoming+titles... |

Additional Information: | © 2012 Springer |

Library of Congress subject classification: | Q Science > QA Mathematics |

Sets: | Departments > Mathematics |

Date Deposited: | 03 Apr 2012 15:42 |

URL: | http://eprints.lse.ac.uk/42951/ |

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