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Planar 4-critical graphs with four triangles
被引:13
|作者:
Borodin, Oleg V.
[1
,2
]
Dvorak, Zdenek
[3
]
Kostochka, Alexandr V.
[1
,4
]
Lidicky, Bernard
[4
]
Yancey, Matthew
[4
]
机构:
[1] Sobolev Inst Math, Novosibirsk 630090, Russia
[2] Novosibirsk State Univ, Novosibirsk 630090, Russia
[3] Charles Univ Prague, Inst Comp Sci, Prague, Czech Republic
[4] Univ Illinois, Urbana, IL 61801 USA
基金:
美国国家科学基金会;
俄罗斯基础研究基金会;
关键词:
D O I:
10.1016/j.ejc.2014.03.009
中图分类号:
O1 [数学];
学科分类号:
0701 ;
070101 ;
摘要:
By the Grunbaum-Aksenov Theorem (extending Grotzsch's Theorem) every planar graph with at most three triangles is 3-colorable. However, there are infinitely many planar 4-critical graphs with exactly four triangles. We describe all such graphs. This answers a question of Erdos from 1990. (C) 2014 Elsevier Ltd. All rights reserved.
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页码:138 / 151
页数:14
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