A direct test for instantaneous collapse of wave functions in configuration space

TL;DR

This paper proposes an experimental test to determine whether wavefunction collapse occurs instantaneously in configuration space by analyzing correlations between two entangled photons after a measurement.

Contribution

It introduces a novel experimental setup using entangled photons and post-selection to directly test the instantaneousness of wavefunction collapse in configuration space.

Findings

Correlation analysis can reveal the nature of wavefunction collapse timing

The proposed test distinguishes between instantaneous and non-instantaneous collapse models

Connections to recent collapse models are discussed

Abstract

Wavefunction collapse is a puzzling aspect of quantum mechanics. Designing a test to confirm the instantaneousness of collapse has turned out to be challenging, especially for collapse in configuration space. We propose a test using two identical, non-local, correlated photons in an interferometer in which a post-selection measurement of one of the photons in its location changes the statistical behavior of the other photon, which is an arbitrarily large distance away, and thus its detectable subsequent behavior. Analysis of the resulting correlations constitutes a test of the instantaneousness (or non-instantaneousness) of collapse. Connections to some of the recent proposed models of collapse are discussed