Triangle-free intersection graphs of line segments with large chromatic number

被引:54
|
作者
Pawlik, Arkadiusz [1 ]
Kozik, Jakub [1 ]
Krawczyk, Tomasz [1 ]
Lason, Michal [1 ,2 ]
Micek, Piotr [1 ]
Trotter, William T. [3 ]
Walczak, Bartosz [1 ,4 ]
机构
[1] Jagiellonian Univ, Fac Math & Comp Sci, Theoret Comp Sci Dept, Krakow, Poland
[2] Polish Acad Sci, Inst Math, Warsaw, Poland
[3] Georgia Inst Technol, Sch Math, Atlanta, GA 30332 USA
[4] Ecole Polytech Fed Lausanne, CH-1015 Lausanne, Switzerland
关键词
Intersection graph; Line segments; Triangle-free; Chromatic number; ARCWISE CONNECTED SETS; PLANE; INTERVALS; RELATIVES;
D O I
10.1016/j.jctb.2013.11.001
中图分类号
O1 [数学];
学科分类号
0701 ; 070101 ;
摘要
In the 1970s Erdos asked whether the chromatic number of intersection graphs of line segments in the plane is bounded by a function of their clique number. We show the answer is no. Specifically, for each positive integer k we construct a triangle-free family of line segments in the plane with chromatic number greater than k. Our construction disproves a conjecture of Scott that graphs excluding induced subdivisions of any fixed graph have chromatic number bounded by a function of their clique number. (C) 2013 Elsevier Inc. All rights reserved.
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页码:6 / 10
页数:5
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