论文标题
由两个抛物线图产生的自由组
Free groups generated by two parabolic maps
论文作者
论文摘要
在本文中，我们考虑了一个由$ {\ rm su}（2,1）$具有不同固定点的两个单位抛物线元素生成的组。我们提供几种保证该小组离散且免费的条件。我们还将对Heisenberg Group中有限$ {\ Mathbb r} $ circle的直径产生结果。
In this paper we consider a group generated by two unipotent parabolic elements of ${\rm SU}(2,1)$ with distinct fixed points. We give several conditions that guarantee the group is discrete and free. We also give a result on the diameter of a finite ${\mathbb R}$-circle in the Heisenberg group.
