The distinguishing number D(G) of a graph is the least integer d such that there is a d-labeling of the vertices of G that is not preserved by any nontrivial automorphism of G. We show that the distinguishing number of the square and higher powers of a connected graph G = K 2 , K 3 with respect to t
Distinguishing geometric graphs
โ Scribed by Michael O. Albertson; Debra L. Boutin
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 196 KB
- Volume
- 53
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
โฆ Synopsis
Abstract
We begin the study of distinguishing geometric graphs. Let G be a geometric graph. An automorphism of the underlying graph that preserves both crossings and noncrossings is called a geometric automorphism. A labeling, f: V(G)โโโ{1, 2,โโฆโ, r}, is said to be rโdistinguishing if no nontrivial geometric automorphism preserves the labels. The distinguishing number of G is the minimum r such that G has an rโdistinguishing labeling. We show that when K~n~ is not the nonconvex K~4~, it can be 3โdistinguished. Furthermore, when nโโฅโ6, there is a K~n~ that can be 1โdistinguished. For nโโฅโ4, K~2,n~ can realize any distinguishing number between 1 and n inclusive. Finally, we show that every K~3,3~ can be 2โdistinguished. We also offer several open questions. ยฉ 2006 Wiley Periodicals, Inc. J Graph Theory 53: 135โ150, 2006
๐ SIMILAR VOLUMES
## Abstract A __geometric graph__ is a simple graph drawn on points in the plane, in general position, with straightline edges. A __geometric__ __homomorphism__ from to is a vertex map that preserves adjacencies and crossings. This work proves some basic properties of geometric homomorphisms and
A geometric graph is a graph drawn in the plane so that the vertices are represented by points in general position and the edges are represented by straight line segments connecting the corresponding points. We show that a geometric graph of n vertices with no k+1 pairwise disjoint edges has at most
## Abstract This paper considers a certain fairly large class of graph invariants and shows that for any invariant in this class, there is a pair of nonisomorphic graphs that have the same invariant. Some explicit examples of such invariants are discussed.