This paper studies circular chromatic numbers and fractional chromatic numbers of distance graphs G(Z , D) for various distance sets D. In particular, we determine these numbers for those D sets of size two, for some special D sets of size three, for
Distance Graphs with Finite Chromatic Number
β Scribed by I.Z. Ruzsa; Zs. Tuza; M. Voigt
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 96 KB
- Volume
- 85
- Category
- Article
- ISSN
- 0095-8956
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β¦ Synopsis
The distance graph G(D) with distance set D={d 1 , d 2 , ...} has the set Z of integers as vertex set, with two vertices i, j Β₯ Z adjacent if and only if |i -j| Β₯ D. We prove that the chromatic number of G(D) is finite whenever inf{d i+1 /d i } > 1 and that every growth speed smaller than this admits a distance set D with infinitechromatic G(D).
π SIMILAR VOLUMES
## Abstract An Erratum has been published for this article in Journal of Graph Theory 48: 329β330, 2005. Let __M__ be a set of positive integers. The distance graph generated by __M__, denoted by __G__(__Z, M__), has the set __Z__ of all integers as the vertex set, and edges __ij__ whenever |__i__
Given positive integers m, k, s with m > sk, let D m,k,s represent the set {1, 2, . . . , m}\{k, 2k, . . . , sk}. The distance graph G(Z , D m,k,s ) has as vertex set all integers Z and edges connecting i and j whenever |i -j| β D m,k,s . This paper investigates chromatic numbers and circular chroma
## Abstract Suppose __D__ is a subset of __R__^+^. The distance graph __G__(__R, D__) is the graph with vertex set __R__ in which two vertices __x__,__y__ are adjacent if |__x__β__y__| β __D__. This study investigates the circular chromatic number and the fractional chromatic number of distance gra
## Abstract We determine the minimum number of edges in a regular connected graph on __n__ vertices, containing a complete subgraph of order __k__ β€ __n__/2. This enables us to confirm and strengthen a conjecture of P. ErdΓΆs on the existence of regular graphs with prescribed chromatic number.