摘要
设G是连通的胞腔嵌入于某闭曲面的图,G的一条左右路是指沿G的边通过交错的选择最左和最右的边作为下一条边走出的一闭途径.本文计数得到了自然嵌入到环面,Klein瓶和射影平面的方格子和三角格子图的左右路数.
Let G be a finite connected graph cellularly embedded in a closed surface. A left-right path in the embedded graph G is obtained by walking on edges of G, alternately selecting as next edge the leftmost edge and the rightmost edge. In this paper, we determine numbers of left-right paths of square and triangular lattices embedded in torus, Klein bottle and projective plane in a natural way.
出处
《数学研究》
CSCD
2011年第3期257-269,共13页
Journal of Mathematical Study
基金
supported by NSFC(10831001)
the Fundamental Research Funds for the Central Universities(2010121007)
关键词
计数
左右路
格子图
闭曲面
环面链环
Enumeration
Left-right paths
Lattices
Closed surfaces
Torus link