The Quantum Eraser Paradox

TL;DR

This paper discusses a proposed extension of the Delayed-Choice Quantum Eraser experiment that creates a paradox under local realist and retrocausal interpretations, challenging the notion of influence on the past in quantum mechanics.

Contribution

It introduces a new experimental extension leading to a paradox, and argues that resolving it requires abandoning retrocausality or the idea of influence on the past.

Findings

The paradox arises under local realist and retrocausal assumptions.

Resolving the paradox involves violating Statistical Independence.

The paper speculates on potential experimental outcomes.

Abstract

The Delayed-Choice Quantum Eraser experiment is commonly interpreted as implying that in quantum mechanics a choice made at one time can influence an earlier event. We here suggest an extension of the experiment that results in a paradox when interpreted using a local realist interpretation combined with backward causation ("retrocausality"). We argue that resolving the paradox requires giving up the idea that, in quantum mechanics, a choice can influence the past, and that it instead requires a violation of Statistical Independence without retrocausality. We speculate what the outcome of the experiment would be.