Comment on: "Low significance of evidence for black hole echoes in gravitational wave data"
Abstract
In a recent publication (1612.00266), we demonstrated that the events in the first observing run of the Advanced LIGO gravitational wave observatory (aLIGO O1) showed tentative evidence for repeating "echoes from the abyss" caused by Planckscale structure near black hole horizons. By considering a phenomenological echo model, we showed that the pure noise hypothesis is disfavored with a pvalue of 1%, i.e. higher amplitude for echoes than those in aLIGO O1 events are only recovered in 1% of random noise realizations. A recent preprint by Westerweck, et al. (1712.09966) provides a careful reevaluation of our analysis which claims "a reduced statistical significance ... entirely consistent with noise". It is a mystery to us why the authors make such a statement, while they also find a pvalue of 2 $\pm$ 1% (given the Poisson error in their estimate) for the same model and dataset. This is perfectly consistent with our results, which would be commonly considered as disfavoring the null hypothesis, or "moderate to significant" evidence for "echoes". Westerweck, et al. also point to diversity of the observed echo properties as evidence for statistical fluke, but such a diversity is neither unique nor surprising for complex physical phenomena in nature.
 Publication:

arXiv eprints
 Pub Date:
 March 2018
 arXiv:
 arXiv:1803.08565
 Bibcode:
 2018arXiv180308565A
 Keywords:

 General Relativity and Quantum Cosmology;
 Astrophysics  High Energy Astrophysical Phenomena;
 High Energy Physics  Theory
 EPrint:
 response to 1712.09966