A sequence of algebraic integer relation numbers which converges to 4

Wonyong Jang, KyeongRo Kim

Let $\alpha \in \mathbb{R}$ and let $$A=\left[\begin{array}{cc}1& 1\\ 0& 1\end{array}\right]\text{and}{B}_{\alpha }=\left[\begin{array}{cc}1& 0\\ \alpha & 1\end{array}\right].$$ The subgroup $G_{\alpha }$ of $\mathrm{SL}_…