五邑大学学报:自然科学版
五邑大學學報:自然科學版
오읍대학학보:자연과학판
Journal of Wuyi University(Natural Science Edition)
2012年
2期
15-17
,共3页
无向图%色数%着色数%围长
無嚮圖%色數%著色數%圍長
무향도%색수%착색수%위장
undirected graph%chromatic number%coloring number%girth
证明了对于围长不少于2k1的图G,其色数X(G)≤c((bk,2k+1+2)n)1/k+1+2,其中c=c(k)且limk→∞ c(k)=1,bt,k是G的booksize.另外还证明了对于围长不少于2k+1的图G,其着色数σ(G)≤[bk,2k+1+1)n/2]1/k+2.
證明瞭對于圍長不少于2k1的圖G,其色數X(G)≤c((bk,2k+1+2)n)1/k+1+2,其中c=c(k)且limk→∞ c(k)=1,bt,k是G的booksize.另外還證明瞭對于圍長不少于2k+1的圖G,其著色數σ(G)≤[bk,2k+1+1)n/2]1/k+2.
증명료대우위장불소우2k1적도G,기색수X(G)≤c((bk,2k+1+2)n)1/k+1+2,기중c=c(k)차limk→∞ c(k)=1,bt,k시G적booksize.령외환증명료대우위장불소우2k+1적도G,기착색수σ(G)≤[bk,2k+1+1)n/2]1/k+2.
In this paper, it is proved that for graph G whose coloring number is X(G)≤c((bk,2k+1+2)n)1/k+1+2 where c=c(k)with limk→∞ c(k)=1and whose girth is at least 2k+1, bl.k is the booksize of G. It is also proved that the coloring number for graph G with girth at least 2k +1 is σ(G)≤[bk,2k+1+1)n/2]1/k+2.