Extremal digraphs whose walks with the same initial and terminal vertices have distinct lengths
发布者:系统管理员发布时间:2012-04-12浏览次数:458
报告题目: | Extremal digraphs whose walks with the same initial and terminal vertices have distinct lengths |
报 告 人: | 詹兴致教授 博士生导师 |
| 华东师范大学数学系 |
报告时间: | 2012年4月16日(周一) 14:30-15:30 |
报告地点: | 九龙湖校区数学系第一报告厅 |
相关介绍: | Let D be a digraph of order n in which any two walks with the same initial vertex and the same terminal vertex have distinct lengths. We prove that D has at most (n+1)^2/4 arcs if n is odd and n(n+2)/4 arcs if n is even. The digraphs attaining this maximum size are determined. The results have equivalent versions for 0-1 matrices.
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