Time symmetry in wave function collapse models

TL;DR

This paper introduces a time-symmetric framework for wave function collapse models, allowing for equivalent forward and backward evolving pictures, but also discusses how initial or final conditions can break this symmetry, leading to asymmetric behaviors.

Contribution

It presents a novel time-symmetric formulation of wave function collapse models and explores how boundary conditions can break this symmetry, affecting the Born rule.

Findings

Time symmetry in collapse models allows equivalent forward and backward descriptions.

Initial or final conditions can break time symmetry, leading to asymmetric outcomes.

The framework provides insights into the role of boundary conditions in quantum evolution.

Abstract

A framework for wave function collapse models that is symmetric under time reversal is presented. Within this framework there are equivalent pictures of collapsing wave functions evolving in both time directions. The backwards-in-time Born rule can be broken by an initial condition on the Universe resulting in asymmetric behaviour. Similarly the forwards-in-time Born rule can in principle be broken by a final condition on the Universe.