Collapse driven by a scalar field without final singularity

Abstract

We explore a collapsing cosmology driven by a scalar field which is minimally coupled to gravity in a spatially flat and spherically symmetric, isotropic and homogeneous space–time, with a variable timescale that avoid the final singularity. The equation of state that describes the collapse is ω=1. We calculate the back-reaction of the space–time during the collapse and the energy density fluctuations related to this back-reaction has a spectral index ns=0, favoring short-wavelengths modes to be detected. The interesting is that the amplitude of these fluctuations increase with time when the collapse is sufficiently strong.