罗美金, 高玉斌. Primitive Exponent of a Class of Two-Colored Digraphs with Two Cycles[J]. 2007, (5): 377-382.DOI:
一类含有两个圈的双色有向图本原指数
摘要
一个双色有向图D是本原的
如果存在非负整数h和k
且h+k0
使得D中的每一对顶点(i
j)都存在从i到j的(h
k)-途径
则称h+k的最小值为D的本原指数.本文考虑了一类特殊的双色有向图
它的未着色图有(m+n)个顶点
包含一个m-圈和一个n-圈
给出了本原条件和指数上界
并对达到指数上界的极图进行了刻划.
Abstract
A two-colored digraph D is primitive if there exist nonnegative integers h and k with h+k0 such that for each pair (i
j) of vertices
there exists an(h
k)-walk in D from i to j.The special two-colored digraphs whose uncolored digraph has m+n vertices and consist of one m-cycle and one n-cycle are considered.Some primitive conditions and the upper bound of the exponents are given.The characterizations of extremal two-colored digraphs are also given.
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references
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