Suppose D ∈ (0, ∞) and 0 < |D| < ∞. The distance graph G(R, D) is the graph with vertex set R, and two vertices x, y are adjacent if |x — y| ∈D. We prove that for every positive integer t > 1 there is a distance set D such that the chromatic number of G(R, D) is t and no proper coloring of G(R, D) with t colors allows monochromatic intervals. This result disproves a conjecture in [2].
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机译:假设D∈(0,∞)并且0 <| D | <∞。距离图G(R,D)是顶点集为R的图,如果| x — y |,则两个顶点x,y相邻。 ∈D。我们证明,对于每个正整数t> 1,都有一个距离集合D,使得G(R,D)的色数为t,并且没有t色的G(R,D)正确着色允许单色间隔。这个结果证明了[2]中的一个猜想。
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