Perturbation theory for post-Newtonian neutron stars
arXiv:2503.03345 · doi:10.1088/1361-6382/ade83f
Abstract
Neutron stars are compact, relativistic bodies that host several extremes of modern physics. An exciting development in recent years has been the opportunity to probe this exotic physics by observing compact-binary coalescences using sensitive gravitational-wave and electromagnetic instruments. To maximise the science inferred from these measurements, we require models that accurately represent the physics. In this study, we consider the post-Newtonian approximation to general relativity for the modelling of neutron-star dynamics, with a particular view to model dynamical tides at the late stages of binary inspiral. We develop the post-Newtonian perturbation equations for a non-rotating star and show that the perturbation problem is Hermitian and therefore derives from a fundamental Lagrangian. Establishing this Lagrangian system leads to a conserved symplectic product and canonical energy for the perturbations. We determine the orthogonality condition for the post-Newtonian oscillation modes, which in turn forms the foundation of a mode-sum representation often used for dynamical tides. Finally, we demonstrate that the perturbation formulation is unique.
arXiv comment16 pages. Accepted for publication in Class. Quantum Gravity
References in corpus (15)
- GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
- Multi-messenger Observations of a Binary Neutron Star Merger
- Gravitational Waves and Gamma-rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A
- GW170817: Measurements of Neutron Star Radii and Equation of State
- A gravitational-wave standard siren measurement of the Hubble constant
- Resonant Oscillations and Tidal Heating in Coalescing Binary Neutron Stars
- Nonlinear mode coupling in rotating stars and the r-mode instability in neutron stars
- On the Progenitor of Binary Neutron Star Merger GW170817
- The rotational modes of relativistic stars: Analytic results
- Quasi-toroidal oscillations in rotating relativistic stars
- Gravitomagnetic tidal resonance in neutron-star binary inspirals
- The sum of Love: Exploring the effective tidal deformability of neutron stars
- General-relativistic treatment of tidal -mode resonances in coalescing binaries of neutron stars. I. Theoretical framework and crust breaking
- General relativistic dynamical tides in binary inspirals, without modes
- Building post-Newtonian neutron stars