Detectability of Gravitational-Wave Memory with LISA: A Bayesian Approach

TL;DR

This paper investigates LISA's potential to detect gravitational-wave memory effects from black hole mergers using Bayesian analysis and simulations, enabling tests of General Relativity.

Contribution

It introduces a Bayesian framework with simulations to assess LISA's ability to detect and characterize gravitational-wave memory effects from individual black hole mergers.

Findings

LISA can potentially detect displacement memory effects in certain black hole merger events.

The analysis estimates the rates at which these effects could be observed during LISA's mission.

Parameter estimation can reconstruct the memory amplitude, testing GR and alternative theories.

Abstract

Gravitational wave (GW) astronomy opens a new venue to explore the universe. Future observatories such as LISA, the Laser Interferometer Space Antenna, are expected to observe previously undetectable fundamental physics effects in signals predicted by General Relativity (GR).One particularly interesting such signal is associated to the displacement memory effect, which corresponds to a permanent deformation of spacetime due to the passage of gravitational radiation. In this work, we explore the ability of LISA to observe and characterize this effect. In order to do this, we use state-of-the-art simulations of the LISA instrument, and we perform a Bayesian analysis to assess the detectability and establish general conditions to claim detection of the displacement memory effect from individual massive black hole binary (MBHB) merger events in LISA. We perform parameter estimation both to explore the impact of the displacement memory effect and to reconstruct its amplitude. We discuss the precision at which such a reconstruction can be obtained thus opening the way to tests of GR and alternative theories. To provide astrophysical context, we apply our analysis to black hole binary populations models and estimate the rates at which the displacement memory effect could be observed within the LISA planned lifetime.