Abstract
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.
Highlights
Inflation is considered as a fundamental component of the standard 3CDM cosmological model characterizing the initial stages of the universe [1,2,3,4]
From our result shown in Eq (42) for P (k), we are going to analyze under which conditions a scale free spectrum can be obtained (this is, when the function Q (z0, zk) does not depend on k and results in a constant)
We have analyzed under which conditions one can recover an essentially scale free spectrum of primordial inhomogeneities, when the standard BD vacuum is replaced by another one that minimizes the renormalized stress–energy tensor via a Hadamard procedure
Summary
Inflation is considered as a fundamental component of the standard 3CDM cosmological model characterizing the initial stages of the universe [1,2,3,4]. One employs a particular collapse mechanism called the continuous spontaneous localization model, where a modification of the Schrödinger equation is proposed, resulting in an objective dynamical reduction of the wave function [22,23,24,25,26] In both approaches, one obtains a prediction for the scalar and tensor power spectra that, in principle, is different from the standard prediction [27,28]. We will follow the first approach to characterize the self-induced collapse, but the framework exposed in the present work can be extended to the second approach Another important feature of the collapse proposal is the adoption of semiclassical gravity [30], which serves to relate the spacetime description in terms of the metric and the degrees of freedom of the inflaton.
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