On the choice of the collapse operator in cosmological Continuous Spontaneous Localisation (CSL) theories

Research paper by Jerome Martin, Vincent Vennin

Indexed on: 03 Mar '21Published on: 02 Mar '21Published in: arXiv - General Relativity and Quantum Cosmology


The Continuous Spontaneous Localisation (CSL) theory in the cosmological context is subject to uncertainties related to the choice of the collapse operator. In this paper, we constrain its form based on generic arguments. We show that, if the collapse operator is even in the field variables, it is unable to induce the collapse of the wavefunction. Instead, if it is odd, we find that only linear operators are such that the outcomes are distributed according to Gaussian statistics, as required by measurements of the cosmic microwave background. We discuss implications of these results for previously proposed collapse operators. We conclude that the cosmological CSL collapse operator should be linear in the field variables.