Detectability of bulk viscosity effects on post-merger gravitational wave signals from binary neutron star mergers
Year: 2026
Type: preprint
Abstract: We investigate bulk viscosity (BV) effects on post-merger gravitational wave (PMGW) signals from binary neutron star (BNS) mergers and their detectability using realistic equation of state (EoS) posteriors constrained by recent progress in gravitational-wave (GW) and X-ray observations, as well as neutron skin thickness measurements. A linear fitting formula based on recent BNS simulations with BV is used to estimate the peak frequency shift of the PMGWs caused by BV effects. Subsequently, we evaluate this peak frequency shift for our set of EoS posterior samples. We use the Fisher information matrix and the dataset of simulated observable events from the ET and CE detector network in an optimistic scenario to estimate the measurement accuracy of the peak frequency. We find that BV effects on PMGWs may be detectable only for EoS models with large values of the symmetry energy slope ($L_{\rm sym}$), as favored by neutron-skin thickness measurements. Thus, the detection of BV effects on PMGWs itself can provide abundant information about the symmetry energy and its slope. However, BV effects on PMGWs are generally weak and may be observed only in some extreme and optimistic cases. Therefore, observations of PMGWs and their analyses may not be able to provide very accurate measurements of the symmetry energy through BV effects.
Source: arXiv (Cornell University)
Institution: Rochester Institute of Technology
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: G1011805105, The Operation and Maintenance of the Laser Interferometer Gravitational Wave Observatory (LIGO), Frameworks: E=mc2 - Enabling Multimessenger astrophysics through Community-driven Cyberinfrastructure, The Construction of the Advanced Laser Interferometer Gravitational Wave Observatory (AdvLIGO), Full Numerical Studies of Extreme and Eccentric Binary Black Hole Mergers, Collaborative Research: WoU-MMA Constraining the nuclear equation of state and population of neutron star mergers through observations of transient and persistent phenomena, Leveraging Curvilinear Coordinates for Long-term and Accurate Simulations of Compact Binary Inspirals and Mergers, WoU-MMA: Inference About Gravitational Wave Sources and Source Populations in the Era of Perpetual Discovery, WoU-MMA: Inference about Gravitational-Wave Sources and Source Populations
OpenAlex ID: W7212085115