Dynamical stability of bootstrapped Newtonian stars

Abstract

We investigate the dynamical stability of bootstrapped Newtonian stars following homologous adiabatic perturbations, focussing on objects of low or intermediate compactness. The results show that for stars with homogeneous densities these perturbations induce some oscillatory behaviour regardless of their compactness, density and adiabatic index, which makes them dynamically stable. In the case or polytropes with density profiles approximated by Gaussian distributions, both stable and unstable behaviours are possible. It was also shown that in the limit in which the profile of the Gaussian density distribution flattens out, the parameter space for which the perturbations result in an oscillatory behaviour increases, which is similar with the case of stars with homogeneous densities.