Abstract
We present numerical simulations treating the ra-di-a-tive dri-ven implosion of density enhancements in molecular cloud cores under the influence of ionizing radiation from massive stars. We performed SPH calculations with initial density perturbations described by Gaussian random fields. We found that large scale perturbations with index -3 in their power spectrum cannot prevent gravitational collapse in the compressed cloud cores, whereas small scale perturbations (power index -1) can at least delay the onset of gravitational instability for a significant fraction of the compression time.
