Violations of the Born rule in cool state-dependent horizons

TL;DR

The paper argues that implementing state-dependent operators to resolve black hole paradoxes leads to significant violations of the Born rule, which could be observable by infalling observers, challenging the consistency of such proposals.

Contribution

It demonstrates that strong forms of state-dependence in black hole physics inherently cause large, observable violations of the Born rule, independent of specific models.

Findings

State-dependence requires violations of the Born rule.

Violations are potentially observable by infalling observers.

Results are general, not tied to specific proposals.

Abstract

The black hole information problem has motivated many proposals for new physics. One idea, known as state-dependence, is that quantum mechanics must be generalized to describe the physics of black holes, and that fixed linear operators do not provide the fundamental description of experiences for infalling observers. Instead, such experiences are to be described by operators with an extra dependence on the global quantum state. We show that any implementation of this idea strong enough to remove firewalls from generic states requires massive violations of the Born rule. We also demonstrate a sense in which such violations are visible to infalling observers involved in preparing the initial state of the black hole. We emphasize the generality of our results; no details of any specific proposal for state-dependence are required.