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arXiv · 1804.04877

A morphology-independent data analysis method for detecting and characterizing gravitational wave echoes

Ka Wa Tsang·Michiel Rollier·Archisman Ghosh·Anuradha Samajdar·Michalis Agathos·Katerina Chatziioannou·Vitor Cardoso·Gaurav Khanna·Chris Van Den Broeck
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Abstract

The ability to directly detect gravitational waves has enabled us to empirically probe the nature of ultra-compact relativistic objects. Several alternatives to the black holes of classical general relativity have been proposed which do not have a horizon, in which case a newly formed object (e.g. as a result of binary merger) may emit echoes: bursts of gravitational radiation with varying amplitude and duration, but arriving at regular time intervals. Unlike in previous template-based approaches, we present a morphology-independent search method to find echoes in the data from gravitational wave detectors, based on a decomposition of the signal in terms of generalized wavelets consisting of multiple sine-Gaussians. The ability of the method to discriminate between echoes and instrumental noise is assessed by inserting into the noise two different signals: a train of sine-Gaussians, and an echoing signal from an extreme mass-ratio inspiral of a particle into a Schwarzschild vacuum spacetime, with reflective boundary conditions close to the horizon. We find that both types of signals are detectable for plausible signal-to-noise ratios in existing detectors and their near-future upgrades. Finally, we show how the algorithm can provide a characterization of the echoes in terms of the time between successive bursts, and damping and widening from one echo to the next.

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Ka Wa Tsang, Michiel Rollier, Archisman Ghosh, Anuradha Samajdar, Michalis Agathos, Katerina Chatziioannou, Vitor Cardoso, Gaurav Khanna, Chris Van Den Broeck. 2018-04-13. A morphology-independent data analysis method for detecting and characterizing gravitational wave echoes. https://doi.org/10.1103/physrevd.98.024023

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