Robust predictions for the large-scale cosmological power deficit from primordial quantum nonequilibrium

TL;DR

This paper demonstrates that a large-scale power deficit in the cosmological power spectrum, predicted by pilot-wave quantum theory, is a robust and general feature under various initial conditions and cosmological scenarios.

Contribution

It shows that the inverse-tangent form of the power deficit remains stable across different initial distributions and the inclusion of an inflationary phase, indicating a robust signature of quantum relaxation.

Findings

The power deficit (k) maintains an inverse-tangent form under various initial conditions.

The inclusion of an inflationary era does not alter the functional form of (k).

The dependence of parameters on pre-inflationary states is consistent with previous results.

Abstract

The de Broglie-Bohm pilot-wave formulation of quantum theory allows the existence of physical states that violate the Born probability rule. Recent work has shown that in pilot-wave field theory on expanding space relaxation to the Born rule is suppressed for long-wavelength field modes, resulting in a large-scale power deficit {\xi}(k) which for a radiation-dominated expansion is found to have an approximate inverse-tangent dependence on k (assuming that the width of the initial distribution is smaller than the width of the initial Born-rule distribution and that the initial quantum states are evenly-weighted superpositions of energy states). In this paper we show that the functional form of {\xi}(k) is robust under changes in the initial nonequilibrium distribution -- subject to the limitation of a subquantum width -- as well as under the addition of an inflationary era at the end of the radiation-dominated phase. In both cases the predicted deficit {\xi}(k) remains an inverse-tangent function of k. Furthermore, with the inflationary phase the dependence of the fitting parameters on the number of superposed pre-inflationary energy states is comparable to that found previously. Our results indicate that, for the assumed broad class of initial conditions, an inverse-tangent power deficit is likely to be a fairly general and robust signature of quantum relaxation in the early universe.