Generalized composition law from 2x2 matrices

摘要

Many results that are difficult can be found more easily by using ageneralization in the complex plane of Einstein's addition law of parallelvelocities. Such a generalization is a natural way to add quantities that arelimited to bounded values. We show how this generalization directly providesphase factors such as the Wigner angle in special relativity and how thisgeneralization is connected in the simplest case with the composition of 2x2 Smatrices.