On a nontrivial knot projection under (1,3) homotopy

被引:2
|
作者
Ito, Noboru [1 ,3 ]
Takimura, Yusuke [2 ]
机构
[1] Waseda Inst Adv Study, Shinjuku Ku, 1-6-1 Nishi Waseda, Tokyo 1698050, Japan
[2] Gakushuin Boys Jr High Sch, Toshima Ku, 1-5-1 Mejiro, Tokyo 1710031, Japan
[3] Univ Tokyo, Grad Sch Math Sci, Meguro Ku, 3-8-1 Komaba, Tokyo 1538914, Japan
关键词
Knot projections; Ostlund conjecture; Reidemeister moves; Spherical curves;
D O I
10.1016/j.topol.2016.07.008
中图分类号
O29 [应用数学];
学科分类号
070104 ;
摘要
In 2001, Ostlund formulated the question: are Reidemeister moves of types 1 and 3 sufficient to describe a homotopy from any generic immersion of a circle in a two-dimensional plane to an embedding of the circle? The positive answer to this question was treated as a conjecture (Ostlund conjecture). In 2014, Hagge and Yazinski disproved the conjecture by showing the first counterexample with a minimal crossing number of 16. This example is naturally extended to counterexamples with given even minimal crossing numbers more than 14. This paper obtains the first counterexample with a minimal crossing number of 15. This example is naturally extended to counterexamples with given odd minimal crossing numbers more than 13. (C) 2016 Elsevier B.V. All rights reserved.
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页码:22 / 28
页数:7
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