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Non-Three-Colourable Common Graphs Exist
被引:32
|作者:
Hatami, Hamed
[1
]
Hladky, Jan
[2
,3
]
Kral, Daniel
[4
]
Norine, Serguei
[5
]
Razborov, Alexander
[6
]
机构:
[1] McGill Univ, Sch Comp Sci, Montreal, PQ, Canada
[2] Charles Univ Prague, Fac Math & Phys, Dept Appl Math, Prague 11800, Czech Republic
[3] Univ Warwick, Dept Comp Sci, DIMAP, Coventry CV4 7AL, W Midlands, England
[4] Charles Univ Prague, Fac Math & Phys, Inst Theoret Comp Sci, Prague 11800, Czech Republic
[5] Princeton Univ, Dept Math, Princeton, NJ 08544 USA
[6] Univ Chicago, Dept Comp Sci, Chicago, IL 60637 USA
来源:
基金:
加拿大自然科学与工程研究理事会;
欧洲研究理事会;
英国工程与自然科学研究理事会;
俄罗斯基础研究基金会;
关键词:
D O I:
10.1017/S0963548312000107
中图分类号:
TP301 [理论、方法];
学科分类号:
081202 ;
摘要:
A graph H is called common if the sum of the number of copies of H in a graph G and the number in the complement of G is asymptotically minimized by taking G to be a random graph. Extending a conjecture of Erdos, Burr and Rosta conjectured that every graph is common. Thomason disproved both conjectures by showing that K-4 is not common. It is now known that in fact the common graphs are very rare. Answering a question of Sidorenko and of Jagger, St' ovicek and Thomason from 1996 we show that the 5-wheel is common. This provides the first example of a common graph that is not three-colourable.
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页码:734 / 742
页数:9
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