摘要
In this paper, a certain class of welded knots K;is considered. By calculating the commutators subgroup of fundamental group Gn of welded knot K;,n ∈ Z;, we show that these welded knots are not equivalent to each other and they are all not classical knots. Secondly, we study some properties of Gn and obtain that Gn is linear, residually finite and Hopfian.
In this paper, a certain class of welded knots K_(2n) is considered. By calculating the commutators subgroup of fundamental group Gn of welded knot K_(2n),n ∈ Z^+, we show that these welded knots are not equivalent to each other and they are all not classical knots. Secondly, we study some properties of Gn and obtain that Gn is linear, residually finite and Hopfian.
基金
The NSF(11329101,11431009,11301135 and 11471245) of China
