Are black holes about information?

TL;DR

This paper critically examines the legitimacy of applying information theory to black hole physics, arguing that the foundational arguments for black hole entropy are flawed and that the empirical basis for these concepts is questionable.

Contribution

It challenges the validity of Bekenstein's argument for black hole entropy and questions the empirical status of black hole thermodynamics in quantum gravity.

Findings

Bekenstein's original argument for black hole entropy is flawed.

The Bekenstein-Hawking formula lacks direct empirical confirmation.

Information-theoretic notions may be problematic in black hole physics.

Abstract

Information theory is increasingly invoked by physicists concerned with fundamental physics, including black hole physics. But to what extent is the application of information theory in those contexts legitimate? Using the case of black hole thermodynamics and Bekenstein's celebrated argument for the entropy of black holes, I will argue that information-theoretic notions are problematic in the present case. Bekenstein's original argument, as suggestive as it may appear, thus fails. This example is particularly pertinent to the theme of the present collection because the Bekenstein-Hawking formula for black hole entropy is widely accepted as 'empirical data' in notoriously empirically deprived quantum gravity, even though the laws of black hole thermodynamics have so far evaded empirical confirmation.