The first author is supported by Development Program for Outstanding Young Teachers in Harbin Institute of Technology (HITQNJS.2009.029); the second author is supported by National Natural Science Foundation of China (Grant No. 15071034)
In this paper, we show the following result: Let Ki be a knot in a closed orientable 3- manifold Mi such that (Mi,Ki) is not homeomorphic to (S^2 × S^1,x0 × S^1), i = 1,2. Suppose that the Euler Characteristic ...
Foundation item: the National Natural Science Foundation of China (No. 15071034); the Foundation of Dalian University of Technology (No. 893322).
In the present paper we discuss some properties of book presentation of spatial graphs, and prove that the book presentation of minimum sheets of a complete graph K2m with even vertices is unique up to sheet translati...