Comments on rotational perturbations of Friedmann universes in Einstein zero-mass scalar theory

Abstract

In addition to the solutions given by Krori et al. for slowly rotating Friedmann models in Einstein zero-mass scalar theory, which correspond to separable w(r, t), we mention that there exists a special class of nonseparable w(r, t)'s that leads to soluble models. We present a particular integral representation of the general solution in terms of an auxiliary function along with two explicit analytic solutions.