Memory effect from neutron star merger counterparts
Abstract
The gravitational-wave (GW) memory effect is a prediction of general relativity, characterized by a permanent change in spacetime geometry. Although it has not yet been observed, next-generation detectors such as the Einstein Telescope (ET) and the Laser Interferometer Space Antenna (LISA) are expected to provide the sensitivity required for its first detection. GW memory comprises two distinct contributions: the nonlinear memory, generated by the self-interaction of GWs, and the linear memory, originating from the anisotropic emission of matter and radiation associated with astrophysical transients. In this work, we quantify both nonlinear and linear memory contributions produced during binary neutron star mergers (BNSs), including those associated with GWs, gamma-ray bursts (GRBs), afterglows, neutrinos, dynamical and disk-wind ejecta, and kilonova emission. We evaluate the detectability of the resulting memory signals with ET and LISA through two applications. First, we apply our analysis to the multi-messenger event GW170817 - GRB 170817A - AT2017gfo. We find that the combined memory signal from this event would have been detectable by ET with a signal-to-noise ratio of 10.7 dominated by the nonlinear memory. We also assess the detectability of the GRB memory across a synthetic population of GRBs, and find that only extreme-energy and jointly favorable configurations could produce a detectable signal in ET. Together, these results demonstrate that while next-generation detectors will probe nonlinear memory, observing linear memory from BNS counterparts will remain elusive except in the most favorable scenarios.
Related
- Production Memory of the 225Ra-225Ac Clock in Neutron-Star Merger Ejecta
- A first-principles binary neutron star merger model of GW170817, GRB170817A, and AT2017gfo
- Neutron Star Merger Universality Relations for a Quark--Hadron Crossover Equation of State
- Detectability of bulk viscosity effects on post-merger gravitational wave signals from binary neutron star mergers
- Δ(1232) isobars and weak-interaction bulk viscosity in neutron-star merger matter
BibTeX
@misc{brabant2026memory,
title = {{Memory effect from neutron star merger counterparts}},
author = {T Brabant and M Pillas and H Inchauspé and Z Lin and F Foucart and M Bulla},
howpublished = {HAL},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.32412},
eprint = {2609.32412},
archivePrefix = {arXiv},
url = {https://hal.science/hal-05781980v1},
}
RIS
TY - UNPB
TI - Memory effect from neutron star merger counterparts
AU - T Brabant
AU - M Pillas
AU - H Inchauspé
AU - Z Lin
AU - F Foucart
AU - M Bulla
PY - 2026
DA - 2026/09/26
PB - HAL
DO - 10.48550/arxiv.2609.32412
UR - https://hal.science/hal-05781980v1
AB - The gravitational-wave (GW) memory effect is a prediction of general relativity, characterized by a permanent change in spacetime geometry. Although it has not yet been observed, next-generation detectors such as the Einstein Telescope (ET) and the Laser Interferometer Space Antenna (LISA) are expected to provide the sensitivity required for its first detection. GW memory comprises two distinct contributions: the nonlinear memory, generated by the self-interaction of GWs, and the linear memory, originating from the anisotropic emission of matter and radiation associated with astrophysical transients. In this work, we quantify both nonlinear and linear memory contributions produced during binary neutron star mergers (BNSs), including those associated with GWs, gamma-ray bursts (GRBs), afterglows, neutrinos, dynamical and disk-wind ejecta, and kilonova emission. We evaluate the detectability of the resulting memory signals with ET and LISA through two applications. First, we apply our analysis to the multi-messenger event GW170817 - GRB 170817A - AT2017gfo. We find that the combined memory signal from this event would have been detectable by ET with a signal-to-noise ratio of 10.7 dominated by the nonlinear memory. We also assess the detectability of the GRB memory across a synthetic population of GRBs, and find that only extreme-energy and jointly favorable configurations could produce a detectable signal in ET. Together, these results demonstrate that while next-generation detectors will probe nonlinear memory, observing linear memory from BNS counterparts will remain elusive except in the most favorable scenarios.
ER -