High distance tangles and tunnel number of knots
High distance tangles and tunnel number of knots
复制标题
高距离缠结和隧道节数
DOI:
10.1017/s0305004117000652
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发表时间:
2018
期刊:
影响因子:
--
通讯作者:
Toshio Saito
中科院分区:
文献类型:
--
作者:
Jung Hoon Lee;Toshio Saito;合田洋;Toshio Saito;合田洋;Toshio Saito
We show that for any integers ti ⩾ 0 (i = 1, 2) and n ⩾ 2, there is a knot K in the 3-sphere with an n-tangle decomposition K = T1∪T2 such that tnl(Ti) = ti (i = 1, 2) and that tnl(K) = tnl(T1) + tnl(T2) + 2n − 1, where tnl(⋅) is the tunnel number. This contains an affirmative answer to an unsolved problem asked by Morimoto.