کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4654117 1632814 2010 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Ramsey numbers of long cycles versus books or wheels
موضوعات مرتبط
مهندسی و علوم پایه ریاضیات ریاضیات گسسته و ترکیبات
پیش نمایش صفحه اول مقاله
Ramsey numbers of long cycles versus books or wheels
چکیده انگلیسی

Given two graphs G1G1 and G2G2, denote by G1∗G2G1∗G2 the graph obtained from G1∪G2G1∪G2 by joining all the vertices of G1G1 to the vertices of G2G2. The Ramsey number R(G1,G2)R(G1,G2) is the smallest positive integer nn such that every graph GG of order nn contains a copy of G1G1 or its complement GcGc contains a copy of G2G2. It is shown that the Ramsey number of a book Bm=K2∗Kmc versus a cycle CnCn of order nn satisfies R(Bm,Cn)=2n−1R(Bm,Cn)=2n−1 for n>(6m+7)/4n>(6m+7)/4 which improves a result of Faudree et al., and the Ramsey number of a cycle CnCn versus a wheel Wm=K1∗CmWm=K1∗Cm satisfies R(Cn,Wm)=2n−1R(Cn,Wm)=2n−1 for even mm and n≥3m/2+1n≥3m/2+1 and R(Cn,Wm)=3n−2R(Cn,Wm)=3n−2 for odd m>1m>1 andn≥3m/2+1n≥3m/2+1 or n>max{m+1,70}n>max{m+1,70} or n≥max{m,83}n≥max{m,83} which improves a result of Surahmat et al. and also confirms their conjecture for large nn. As consequences, Ramsey numbers of other sparse graphs are also obtained.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: European Journal of Combinatorics - Volume 31, Issue 3, April 2010, Pages 828–838
نویسندگان
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