For all n $ S or 9 (mod 12) the genu3 :lf the granh II, x K, is shown t#c> be equal to the lower hound given by the Euler Formula. Consider two disjoint copies of a complete graph K,, the first t&h vertices 1,2, . . -, n, the second with vertices l', 2', . . .) n'. Then join vertex i with vertex i'
The genus of Kn − K2
✍ Scribed by Mark Jungerman
- Publisher
- Elsevier Science
- Year
- 1975
- Tongue
- English
- Weight
- 324 KB
- Volume
- 18
- Category
- Article
- ISSN
- 0095-8956
No coin nor oath required. For personal study only.
📜 SIMILAR VOLUMES
The problem of construction of a nonorientable triangular embedding of the graph K, -K 2, n -8(rood 12), n >/ 1, was posed in the course of the proof of the Map Colour Theorem, but it remained an open problem. In this paper the embedding is constructed.
Our main result is that a 1971 conjecture due to Paul Kainen is false. Kainen's conjecture implies that the genus 2 crossing number of K 9 is 3. We disprove the conjecture by showing that the actual value is 4. The method used is a new one in the study of crossing numbers, involving proof of the imp
## Abstract We exhibit cyclic (__K~v~__, __C~k~__)‐designs with __v__ > __k__, __v__ ≡ __k__ (mod 2__k__), for __k__ an odd prime power but not a prime, and for __k__ = 15. Such values were the only ones not to be analyzed yet, under the hypothesis __v__ ≡ __k__ (mod 2__k__). Our construction avail