Low significance of evidence for black hole echoes in gravitational wave data

TL;DR

This study reanalyzed gravitational wave data to test claims of black hole echoes, finding no significant evidence and concluding that previous claims were likely due to noise.

Contribution

The paper critically reevaluates prior evidence for black hole echoes, demonstrating that earlier claims lack statistical significance with improved analysis methods.

Findings

No statistically significant evidence for black hole echoes

Previous claims are consistent with noise fluctuations

Supports the null hypothesis of no echoes in gravitational wave data

Abstract

Recent detections of merging black holes allow observational tests of the nature of these objects. In some proposed models, non-trivial structure at or near the black hole horizon could lead to echo signals in gravitational wave data. Recently, Abedi et al. claimed tentative evidence for repeating damped echo signals following the gravitational-wave signals of the binary black hole merger events recorded in the first observational period of the Advanced LIGO interferometers. We reanalyse the same data, addressing some of the shortcomings of their method using more background data and a modified procedure. We find a reduced statistical significance for the claims of evidence for echoes, calculating increased p-values for the null hypothesis of echo-free noise. The reduced significance is entirely consistent with noise, and so we conclude that the analysis of Abedi et al. does not provide any observational evidence for the existence of Planck-scale structure at black hole horizons.