共查询到20条相似文献,搜索用时 78 毫秒
1.
2.
3.
给定染色数的无符号Laplace谱半径 总被引:2,自引:0,他引:2
设Gkn(k≥2)为n阶的染色数为k的连通图的集合.本文确定了Gkn中具有极大无符号Laplace谱半径的图,即k=2时为完全二部图,k≥3时为Turn图.本文也讨论了Gkn中的具有极小无符号Laplace谱半径的图,对k≤3的情形给出了此类图的刻画. 相似文献
4.
5.
6.
设k,n为两个确定的正整数.本文得到了当1≤k≤n-7时恰有k个悬挂点的n阶连通三圈图的最大拟拉普拉斯谱半径的唯一极图,也得到了当1≤k≤n-5时恰有k个悬挂点的n阶连通双圈图的最大拟拉普拉斯谱半径的唯一极图. 相似文献
7.
双圈图按谱半径的排序 总被引:1,自引:0,他引:1
一个n阶简单连通图G被称为双圈图,如果它的边数是n+1.记B(n)是n阶双圈图的全体.本文确定了B(n)(n≥20)中谱半径的第六大至第十大值和对应的图. 相似文献
8.
单圈偶图是边数等于顶点数的简单连通偶图.Δ(G)表示图G的最大度.文中给出了最大度为Δ(≥n+1/2)的n阶单圈偶图的谱半径的上界,并刻画了达到该上界的图.文中还证明了当Δ(G)≥[(2n+1)/3]+1时,n(≥8)阶单圈偶图G的谱半径随着最大度的递增而严格递增,并在此基础上给出了谱半径排在前17位的n(≥16)阶单圈偶图. 相似文献
9.
设U*为一个未定向的n个顶点上的单圈混合图,它是由一个三角形在其某个顶点上附加n-3个悬挂边而获得.在文[Largest eigenvalue of a unicyclic mixed graph,Applied Mathematics A Journal of Chinese Universities(Ser.B),2004,19(2):140-148]中,作者证明了:在相差符号同构意下,在所有n个顶点上的单圈混合图中,U*是唯一的达到最大Laplace谱半径的混合图.本文应用非负矩阵的Perron向量,给出上述结论的一个简单的证明. 相似文献
10.
三圈图是边数等于顶点数加2的简单连通图.在所有n阶三圈图的补图中,哪一个的谱半径最大?文中给出了n阶三圈图的补图的谱半径的上界,并刻画了唯一的达到该上界的图. 相似文献
11.
F. J. Schuurmann P. R. Krishnaiah A. K. Chattopadhyay 《Journal of multivariate analysis》1973,3(4):445-453
In this paper, the authors cosider the derivation of the exact distributions of the ratios of the extreme roots to the trace of the Wishart matrix. Also, exact percentage points of these distributions are given and their applications are discussed. 相似文献
12.
《European Journal of Operational Research》2005,161(2):377-385
The valuation of levered investment in the practice is made with the WACC approach, even if the superior technique of the APV is available. The paper shows that the APV can be interpreted as the arbitrage free value of the portfolio made by an investment and a supporting loan. Therefore the WACC evaluation, generally different from the APV, allows for arbitrage. We provide various conditions which completely characterize the sign of the error as a functions of all the variables entering the model. 相似文献
13.
用常微分方程模型分析预防和隔离措施对SARS发病率的影响 总被引:2,自引:2,他引:0
通过建立常微分方程模型 ,分析了预防和隔离措施对 SARS发病率的影响 ,并把计算结果与实际统计数据进行了比较 ,结果表明 ,及时高效的预防和隔离措施能够有效地控制 SARS的传播 . 相似文献
14.
Hans Jürgen Borchers 《Annales Henri Poincare》2002,3(1):1-17
The spectrum of the translations in local quantum field theory will be analyzed in order to show that in a positive energy representation without vacuum vector and with lowest mass m1 there is no gap in the spectrum which is larger than 2m1. In particular in a zero mass representation there is no hole at all. These results are obtained with methods of analytic functions of several complex variables. 相似文献
15.
Presented by A. F. Pixley. 相似文献
16.
《Chaos, solitons, and fractals》2001,12(6):1101-1109
Two recent findings necessitate a closer look at the existing standard models of particle physics and cosmology. These are the discovery of neutrino oscillation, and hence a non-zero mass on the one hand and, on the other, observations of distant supernovae which indicate that contrary to popular belief, the universe would continue to expand for ever, possibly accelerating in the process. In this paper it is pointed out that relatively recent studies which indicate a stochastic, quantum vacuum underpinning and a fractal structure for space time, reconcile both of the recent observations, harmoniously. 相似文献
17.
18.
19.
20.
A. G. Shukhov 《Mathematical Notes》1999,65(4):510-515
Let {
} be a sequence of finitely presented groups with generating setA={a1, …, am}, and letRk be the symmetrized set of words over the alphabetA∪A−1 obtained from the defining words and their inverses by all cyclic shifts. We shall assume that the words inRk are cyclically irreducible, and their lengths tend to ∞ ask increases. In the paper, it is proved that ifRk satisfies the small cancellation conditionC'(1/6) and the number of relators increases not very rapidly with increasingk, then the growth rate ψ(Gk) tends to 2m−1 ask→∞.
Translated fromMatematicheskie Zametki, Vol. 65, No. 4, pp. 611–617, April, 1999. 相似文献