๐”– Bobbio Scriptorium
โœฆ   LIBER   โœฆ

Minimal embeddings in the projective plane

โœ Scribed by Randby, Scott P.


Publisher
John Wiley and Sons
Year
1997
Tongue
English
Weight
161 KB
Volume
25
Category
Article
ISSN
0364-9024

No coin nor oath required. For personal study only.

โœฆ Synopsis


We show that if G is a graph embedded on the projective plane in such a way that each noncontractible cycle intersects G at least n times and the embedding is minimal with respect to this property (i.e., the representativity of the embedding is n), then G can be reduced by a series of reduction operations to an n ร— n ร— n projective grid. The reduction operations consist of changing a triangle of G to a triad, changing a triad of G to a triangle, and several others. We also show that if every proper minor of the embedding has representativity < n (i.e., the embedding is minimal), then G can be obtained from an n ร— n ร— n projective grid by a series of the two reduction operations described above. Hence every minimal embedding has the same number of edges.


๐Ÿ“œ SIMILAR VOLUMES


Y-rotation in k-minimal quadrangulations
โœ Atsuhiro Nakamoto; Yusuke Suzuki ๐Ÿ“‚ Article ๐Ÿ“… 2011 ๐Ÿ› John Wiley and Sons ๐ŸŒ English โš– 190 KB

Let G be a quadrangulation on a surface, and let f be a face bounded by a 4-cycle abcd. A face-contraction of f is to identify a and c (or b and d) to eliminate f . We say that a simple quadrangulation G on the surface is k-minimal if the length of a shortest essential cycle is k(โ‰ฅ 3), but any face-

Embeddings of Curves in the Plane
โœ Vladimir Shpilrain; Jie-Tai Yu ๐Ÿ“‚ Article ๐Ÿ“… 1999 ๐Ÿ› Elsevier Science ๐ŸŒ English โš– 88 KB

## w x Let K x, y be the polynomial algebra in two variables over a field K of characteristic 0. In this paper, we contribute toward a classification of two-variable ลฝ w x. polynomials by classifying up to an automorphism of K x, y polynomials of the e., polynomials whose New- . ton polygon is e

Classification of Embeddings of the Flag
โœ Joseph A. Thas; Hendrik Van Maldeghem ๐Ÿ“‚ Article ๐Ÿ“… 2000 ๐Ÿ› Elsevier Science ๐ŸŒ English โš– 156 KB

The flag geometry 1=(P, L, I) of a finite projective plane 6 of order s is the generalized hexagon of order (s, 1) obtained from 6 by putting P equal to the set of all flags of 6, by putting L equal to the set of all points and lines of 6, and where I is the natural incidence relation (inverse conta

Classification of Embeddings of the Flag
โœ Joseph A. Thas; Hendrik Van Maldeghem ๐Ÿ“‚ Article ๐Ÿ“… 2000 ๐Ÿ› Elsevier Science ๐ŸŒ English โš– 214 KB

The flag geometry 1=(P, L, I) of a finite projective plane 6 of order s is the generalized hexagon of order (s, 1) obtained from 6 by putting P equal to the set of all flags of 6, by putting L equal to the set of all points and lines of 6, and where I is the natural incidence relation (inverse conta