Probing Neutron Star Equation of State Universality with Gravitational Waves
Abstract
Current neutron star equation-of-state inferences assume that a common equation of state describes all neutron stars. However, {poorly understood dense-matter physics may give rise to distinct long-lived stellar subpopulations following different mass--tidal-deformability relations, invalidating this assumption. In this Letter, we demonstrate that next-generation gravitational-wave observatories enable neutron star equation-of-state universality to be transformed from an assumption into a testable hypothesis. By combining hierarchical Bayesian inference with a piecewise-polytropic parametrization of the neutron star equation of state, we establish a framework for testing equation-of-state universality with next-generation gravitational-wave observatories. We find that about 30 (50) loud binary neutron star mergers with network SNRs above 100 are sufficient to provide compelling evidence for departures from equation-of-state universality, even if only 20% (10%) of the population exhibits one of the representative non-universality parametrizations considered here.
Related
- Neutron Star Merger Universality Relations for a Quark--Hadron Crossover Equation of State
- A New Scaling of Neutron Star Tidal Deformability for Directly Probing the Central Equation of State Parameter
- Constraining the Equation of State of Neutron Stars with third-generation Gravitational Wave detectors
- Constraining equation of state of neutron star using neutron star-black hole mergers
- Statistical Analysis of Neutron Star Cooling: Implications for the Nuclear Equation of State and Nucleon Pairing
BibTeX
@misc{tiwari2026probing,
title = {{Probing Neutron Star Equation of State Universality with Gravitational Waves}},
author = {Praveer Tiwari and Ajit Kumar Mehta and K. G. Arun},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.05118},
eprint = {2609.05118},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.05118},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Probing Neutron Star Equation of State Universality with Gravitational Waves
AU - Praveer Tiwari
AU - Ajit Kumar Mehta
AU - K. G. Arun
PY - 2026
DA - 2026/09/04
PB - arXiv
DO - 10.48550/arxiv.2609.05118
UR - https://arxiv.org/abs/2609.05118
AB - Current neutron star equation-of-state inferences assume that a common equation of state describes all neutron stars. However, {poorly understood dense-matter physics may give rise to distinct long-lived stellar subpopulations following different mass--tidal-deformability relations, invalidating this assumption. In this Letter, we demonstrate that next-generation gravitational-wave observatories enable neutron star equation-of-state universality to be transformed from an assumption into a testable hypothesis. By combining hierarchical Bayesian inference with a piecewise-polytropic parametrization of the neutron star equation of state, we establish a framework for testing equation-of-state universality with next-generation gravitational-wave observatories. We find that about 30 (50) loud binary neutron star mergers with network SNRs above 100 are sufficient to provide compelling evidence for departures from equation-of-state universality, even if only 20% (10%) of the population exhibits one of the representative non-universality parametrizations considered here.
ER -