fractional linear transformation

A transformation of the form w = f(z) = (a z + b)/(c z + d), where a, b, c, d element C and a d - b c!=0, is a conformal mapping called a linear fractional transformation.

Cayley transform | Kleinian group | modular group Γ | Möbius transformation | Schwarz's lemma | symmetry principle | unimodular transformation