Donghi Lee

activity

20152020

collaborators

3 papers

math.GT2020

Classification of parabolic generating pairs of Kleinian groups with two parabolic generators

Shunsuke Aimi, Donghi Lee, Shunsuke Sakai +1

We give an alternative proof to Agol's classification of parabolic generating pairs of non-free Kleinian groups generated by two parabolic transformations. As an application, we gi…

math.GR2019

Non-residually finite groups hyperbolic relative to residually finite subgroups

Jan Kim, Donghi Lee

Let $m$ and $k$ be integers such that $∣ m ∣, ∣ k ∣ > 1$ and $g cd (m, k) = 1$ . We show that all Baumslag-Solitar groups $B S (m, mk)$ are non-residually finite groups hyperbolic relative…

math.GR2015

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 $2$ -bridge sphere in an even Heckoid orbifold for the trivial knot to be null-homotopi…