Detecting gravitational-wave memory with LIGO: implications of GW150914

TL;DR

This paper discusses how Advanced LIGO can detect gravitational-wave memory through multiple binary black hole merger observations, emphasizing the role of higher-order modes in improving detection and parameter estimation.

Contribution

It introduces methods for detecting gravitational-wave memory with LIGO and highlights the importance of higher-order modes in parameter estimation and mode detection.

Findings

Advanced LIGO may detect gravitational-wave memory with 35-90 events.

Higher-order modes are crucial for accurate parameter estimation.

Methods can also detect higher-order modes before reaching design sensitivity.

Abstract

It may soon be possible for Advanced LIGO to detect hundreds of binary black hole mergers per year. We show how the accumulation of many such measurements will allow for the detection of gravitational-wave memory: a permanent displacement of spacetime that comes from strong-field, general relativistic effects. We estimate that Advanced LIGO operating at design sensitivity may be able to make a signal-to-noise ratio 3(5) detection of memory with ~35 (90) events with masses and distance similar to GW150914. We highlight the importance of incorporating higher-order gravitational-wave modes for parameter estimation of binary black hole mergers, and describe how our methods can also be used to detect higher-order modes themselves before Advanced LIGO reaches design sensitivity.