New BCH-like relations of the su(1,1), su(2) and so(2,1) Lie algebras

Abstract

In this work we demonstrate new BCH-like relations involving the generators of the su(1,1), su(2) and so(2,1) Lie algebras. We use our results to obtain in a straightforward way the composition of an arbitrary number of elements of the corresponding Lie groups. In order to make a self-consistent check of our results, as a first application we recover the non-trivial composition law of two arbitrary squeezing operators. As a second application, we show how our results can be used to compute the time evolution operator of physical systems described by time-dependent hamiltonians given by linear combinations of the generators of the aforementioned Lie algebras.