## Abstract In 1959, even before the Four‐Color Theorem was proved, Grötzsch showed that planar graphs with girth at least 4 have chromatic number at the most 3. We examine the fractional analogue of this theorem and its generalizations. For any fixed girth, we ask for the largest possible fraction
Chromatic number, girth and maximal degree
✍ Scribed by Béla Bollobás
- Publisher
- Elsevier Science
- Year
- 1978
- Tongue
- English
- Weight
- 544 KB
- Volume
- 24
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
✦ Synopsis
It is proved that for every k a4 there is a A(k) such that for eve:y g there is a graph G with maximal degree at most A(k), chromatic number at least k and girth at least g. In fact, for a fixed k, the restriction of the maximal degree to A(k) does not seem to slow down the ptiih of the maximal girth of a k-chromatic graph of order n as n -+ w
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