A Nonconvex Nonorientable Crossing Number Sequence  

作　　者：Han REN Jing REN 

机构地区：[1]Department of Mathematics,East China Normal University,Shanghai 200062,P.R.China [2]Economics and Management School of Wuhan University,Hubei 430072,P.R.China

出　　处：《Journal of Mathematical Research and Exposition》2010年第6期985-991,共7页数学研究与评论（英文版）

基　　金：Supported by the National Natural Science Foundation of China (Grant No.10671073);the Science and Technology Commission of Shanghai Municipality (Grant No.07XD14011)

摘　　要：It is well known that finding the crossing number of a graph on nonplanar surfaces is very difficult.In this paper we study the crossing number of the circular graph C（10,4） on the projective plane and determine the nonorientable crossing number sequence of C（10,4）.On the basis of the result,we show that the nonorientable crossing number sequence of C（10,4） is not convex.It is well known that finding the crossing number of a graph on nonplanar surfaces is very difficult.In this paper we study the crossing number of the circular graph C（10,4） on the projective plane and determine the nonorientable crossing number sequence of C（10,4）.On the basis of the result,we show that the nonorientable crossing number sequence of C（10,4） is not convex.

关 键 词：crossing number EMBEDDING non-orientable surface. 

分 类 号：O175.5[理学—数学]