Discussions about the landscape of possibilities for treatments of cosmic inflation involving continuous spontaneous localization models

TL;DR

This paper explores various theoretical possibilities for applying continuous spontaneous localization (CSL) models to cosmic inflation, highlighting how different assumptions impact conclusions and emphasizing the need for a relativistic quantum gravity framework.

Contribution

It systematically examines different approaches and parameter choices in applying CSL to inflation, warning against premature conclusions based on non-relativistic extrapolations.

Findings

Choices in CSL application significantly affect inflationary predictions.

Incompatibilities with CMB data depend on specific extrapolation assumptions.

A fully relativistic CSL theory is needed for definitive results.

Abstract

In this work we consider a wide variety of alternatives opened when applying the continuous spontaneous localization (CSL) dynamical collapse theory to the inflationary era. The definitive resolution of many of the issues discussed here will have to await, not only for a general relativistic CSL theory, but for a fully workable theory of quantum gravity. Our concern here is to explore these issues, and to warn against premature conclusions. This exploration includes: two different approaches to deal with quantum field theory and gravitation, the identification of the collapse-generating operator and the general nature and values of the parameters of the CSL theory. All the choices connected with these issues have the potential to dramatically alter the conclusions one can draw. We also argue that the incompatibilities found in a recent paper, between the CSL parameter values and the CMB observational data, are associated with specific choices made for the extrapolation to the cosmological context of the CSL theory (as it is known to work in non-relativistic laboratory situations) which do not represent the most natural ones.