We show that every drawing of C m \_C n with either the m n-cycles pairwise disjoint or the n m-cycles pairwise disjoint has at least (m&2) n crossings, for every m, n satisfying n m 3. This supports the long standing conjecture by Harary et al. that the crossing number of C m \_C n is (m&2) n.
Drawings of Cm×Cn with One Disjoint Family II
✍ Scribed by Hector A. Juarez; Gelasio Salazar
- Book ID
- 102584407
- Publisher
- Elsevier Science
- Year
- 2001
- Tongue
- English
- Weight
- 99 KB
- Volume
- 82
- Category
- Article
- ISSN
- 0095-8956
No coin nor oath required. For personal study only.
✦ Synopsis
A long-standing conjecture states that the crossing number of the Cartesian product of cycles C m _C n is (m&2) n, for every m, n satisfying n m 3. A crossing is proper if it occurs between edges in different principal cycles. In this paper drawings of C m _C n with the principal n-cycles pairwise disjoint or the principal m-cycles pairwise disjoint are analyzed, and it is proved that every such drawing has at least (m&2) n proper crossings. As an application of this result, we prove that the crossing number of C m _C n is at least (m&2) nÂ2, for all integers m, n such that n m 4. This is the best general lower bound known for the crossing number of C m _C n .
📜 SIMILAR VOLUMES
The design of a 10 cm × 10 cm flow cell for the soluble lead acid flow battery is described. A number of extended charge/discharge cycling experiments are presented to demonstrate the capability of the battery to cycle over lengthy periods and to identify the problems that limit the number of cycles
## A procedure for evaluation and calculation of the rate constants for a direct two-step chemical reaction using the time-dependence of an analytical property proportional to the intermediate concentration is described. The method does not require that the intermediate properties be known. The calc