On the impossibility of observational confirmation of black holes

TL;DR

Despite recent observational data supporting black hole candidates, fundamental limits in general relativity prevent conclusive observational confirmation of black holes' existence.

Contribution

The paper argues that observational data cannot definitively confirm black holes due to fundamental theoretical limits in general relativity.

Findings

Current data support black hole candidates but do not confirm black holes.

Observations can only exclude some alternative models, not prove black holes.

Fundamental theoretical limits prevent observational confirmation of black holes.

Abstract

General relativity has achieved remarkable experimental and observational success. Critically, recent data from the LIGO-Virgo-KAGRA, Event Horizon Telescope, and GRAVITY collaborations are often credited with \textit{demonstrating} the existence of black holes, but in fact they only provide evidence for objects that should be regarded as black hole candidates. While current data are in striking agreement with the predictions for Kerr black holes, they can only rule out specific alternative models of compact objects rather than provide conclusive proof of black holes. More fundamentally, and independent of whether or not black holes exist, general relativity itself imposes limits on what can be observationally established. Essentially, no observational data is sufficient to confirm the existence of black holes.