Within the framework of inflationary models that incorporate a spontaneous
reduction of the wave function for the emergence of the seeds of cosmic
structure, we study the effects on the primordial scalar power spectrum by
choosing a novel initial quantum state that characterizes the perturbations of
the inflaton. Specifically, we investigate under which conditions one can
recover an essentially scale free spectrum of primordial inhomogeneities when
the standard Bunch-Davies vacuum is replaced by another one that minimizes the
renormalized stress-energy tensor via a Hadamard procedure. We think that this
new prescription for selecting the vacuum state is better suited for the
self-induced collapse proposal than the traditional one in the semiclassical
gravity picture. We show that the parametrization for the time of collapse,
considered in previous works, is maintained. Also, we obtain an angular
spectrum for the CMB temperature anisotropies consistent with the one that best
fits the observational data. Therefore, we conclude that the collapse mechanism
might be of a more fundamental character than previously suspected.Comment: 17 pages, 2 figures. Extended and revised version. To appear in
Physics Letters