Elliptic element of PSL2(R)
= Elliptic element of PSL2(R)
{title2=$|\operatorname{tr}A|<2$}
= Elliptic Möbius transformation
{synonym}
A real <Möbius transformation> represented by $A\in\mathrm{SL}_2(\mathbb R)$ with $|\operatorname{tr}A|<2$. It fixes a point of the <Poincare half-plane model>; an integral matrix of this type has <trace> $0$ or $\pm1$. In the <Poincare disc model>, moving its fixed point to zero makes it a rotation about zero.