Journal of Combinatorial Theory Series A ( IF 0.9 ) Pub Date : 2020-01-23 , DOI: 10.1016/j.jcta.2019.105188 Dmitriy Zakharov
Let be a graph whose vertices are all r-element subsets of an n-element set, in which two vertices are adjacent if they intersect in exactly s elements. In this paper we study chromatic numbers of with being fixed constants and n tending to infinity. Using a recent result of Keevash on existence of designs we deduce an inequality for with fixed constants. This inequality gives sharp upper bounds for . Also we develop an elementary approach to this problem and prove that without use of Keevash's results.
Some bounds on the list chromatic number of are also obtained.
中文翻译:
Kneser型图的色数
让 是其顶点是所有的曲线图ř一个的子集-元素Ñ -元素集合,其中两个顶点是如果它们在正好相交相邻小号元件。在本文中,我们研究了 与 是固定常数且n趋于无穷大。利用Keevash在设计存在方面的最新结果,我们得出了不等式 对于 与 固定常数。这种不平等为。此外,我们还针对该问题开发了一种基本方法,并证明了 不使用Keevash的结果。
列表色数上的一些界限 也获得。