83 citations · 139 across the 28 of their papers we have counts for
9 papers · 1 filter
A family of two generator non-Hopfian groups
Donghi Lee, Makoto Sakuma
We construct -generator non-Hopfian groups , where each has a specific presentation $G_m=\langle a, b \, | \, u_{r_{m,0}}=u_{r_{m,1}}=u_{r_{m,2}}= \…
Parabolic generating pairs of genus-one 2-bridge knot groups
Donghi Lee, Makoto Sakuma
We show that any parabolic generating pair of a genus-one hyperbolic 2-bridge knot group is equivalent to the upper or lower meridian pair. As an application, we obtain a complete…
Simple loops on 2-bridge spheres in Heckoid orbifolds for the trivial knot
Donghi Lee, Makoto Sakuma
In this paper, we give a necessary and sufficient condition for an essential simple loop on a -bridge sphere in an even Heckoid orbifold for the trivial knot to be null-homotopi…
Homotopically equivalent simple loops on 2-bridge spheres in Heckoid orbifolds for 2-bridge links (II)
Donghi Lee, Makoto Sakuma
In this paper and its prequel, we give a necessary and sufficient condition for two essential simple loops on a 2-bridge sphere in an even Heckoid orbifold for a 2-bridge link to b…
Homotopically equivalent simple loops on 2-bridge spheres in Heckoid orbifolds for 2-bridge links (I)
Donghi Lee, Makoto Sakuma
In this paper and its sequel, we give a necessary and sufficient condition for two essential simple loops on a 2-bridge sphere in an even Heckoid orbifold for a 2-bridge link to be…
Epimorphisms from 2-bridge link groups onto Heckoid groups (II)
Donghi Lee, Makoto Sakuma
In Part I of this series of papers, we made Riley's definition of Heckoid groups for 2-bridge links explicit, and gave a systematic construction of epimorphisms from 2-bridge link…