𝔖 Bobbio Scriptorium
✦   LIBER   ✦

A note on defective colorings of graphs in surfaces

✍ Scribed by Dan Archdeacon


Publisher
John Wiley and Sons
Year
1987
Tongue
English
Weight
139 KB
Volume
11
Category
Article
ISSN
0364-9024

No coin nor oath required. For personal study only.

✦ Synopsis


A graph is (rn, k)-colorable if its vertices can be colored with rn colors in such a way that each vertex is adjacent to at most k vertices of the same color as itself. In a recent paper Cowen. Cowen, and Woodall proved that, for each compact surface S, there exists an integer k = k(S) such that every graph in S can be (4, k)-colored. They also conjectured that the 4 could be replaced by 3. In this note we prove their conjecture.


πŸ“œ SIMILAR VOLUMES


The number of defective colorings of gra
✍ Tom Rackham πŸ“‚ Article πŸ“… 2010 πŸ› John Wiley and Sons 🌐 English βš– 99 KB πŸ‘ 1 views

A (k, 1)-coloring of a graph is a vertex-coloring with k colors such that each vertex is permitted at most 1 neighbor of the same color. We show that every planar graph has at least c n distinct (4, 1)-colorings, where c is constant and β‰ˆ 1.466 satisfies 3 = 2 +1. On the other hand for any >0, we gi

Note on a new coloring number of a graph
✍ P. HorΓ‘k; J. Ε irÑň πŸ“‚ Article πŸ“… 1980 πŸ› John Wiley and Sons 🌐 English βš– 112 KB πŸ‘ 1 views

## Abstract The distance coloring number __X__~__d__~(__G__) of a graph __G__ is the minimum number __n__ such that every vertex of __G__ can be assigned a natural number __m__ ≀ __n__ and no two vertices at distance __i__ are both assigned __i__. It is proved that for any natural number __n__ ther

A Note on Almost Regular Graphs
✍ M. Of Hofmeister Munich πŸ“‚ Article πŸ“… 1994 πŸ› John Wiley and Sons 🌐 English βš– 136 KB

It can easily be seen that a conjecture of RUNGE does not hold for a class of graphs whose members will be called "almost regular". This conjecture is replaced by a weaker one, and a classification of almost regular graphs is given.