It is easy to see that planar graphs without 3-cycles are 3-degenerate. Recently, it was proved that planar graphs without 5-cycles are also 3-degenerate. In this paper it is shown, more surprisingly, that the same holds for planar graphs without 6-cycles.
Note on graphs without repeated cycle lengths
✍ Scribed by Chen, Guantao; Lehel, Jen�; Jacobson, Michael S.; Shreve, Warren E.
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 225 KB
- Volume
- 29
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
✦ Synopsis
In this note we prove that every 2-connected graph of order n with no repeated cycle lengths has at most n + 2(n -2) -1 edges and we show this result is best possible with the correct order of magnitude on √ n. The 2connected case is also used to give a quick proof of Lai's result on the general case.
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