Bounds for rectilinear crossing numbers
β Scribed by Daniel Bienstock; Nathaniel Dean
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 780 KB
- Volume
- 17
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
β¦ Synopsis
Abstract
A rectilinear drawing of a graph is one where each edge is drawn as a straightβline segment, and the rectilinear crossing number of a graph is the minimum number of crossings over all rectilinear drawings. We describe, for every integer k β₯ 4, a class of graphs of crossing number k, but unbounded rectilinear crossing number. This is best possible since the rectilinear crossing number is equal to the crossing number whenever the latter is at most 3. Further, if we consider drawings where each edge is drawn as a polygonal line segment with at most one break point, then the resulting crossing number is at most quadratic in the regular crossing number. Β© 1993 John Wiley & Sons, Inc.
π SIMILAR VOLUMES
## Abstract We show that if a graph has maximum degree __d__ and crossing number __k__, its rectilinear crossing number is at most __O__(__dk__^2^). Hence for graphs of bounded degree, the crossing number and the rectilinear crossing number are bounded as functions of one another. We also obtain a
In this paper we prove parts of a conjecture of Herzog giving lower bounds on the rank of the free modules appearing in the linear strand of a graded kth syzygy module over the polynomial ring. If in addition the module is β«ήβ¬ n -graded we show that the conjecture holds in full generality. Furthermo