Gravitational Wave Strain and Orbital Dynamics of Binary Pulsars from LIGO-Virgo to LISA

TL;DR

This paper calculates gravitational wave strains and orbital dynamics for binary pulsars using current and upcoming detectors, providing insights into merger rates and neutron star physics through multi-band gravitational wave observations.

Contribution

It offers detailed calculations of gravitational wave strain amplitudes, orbital parameters, and merger rates, integrating data from LIGO-Virgo and LISA to enhance understanding of binary pulsar evolution.

Findings

Gravitational wave strain amplitudes range from 3.0 to 73 x10^{-22} across 0.66 to 5.87 x10^{-4} Hz.

Predicted periastron advance rates from 1.6 to 80.5 deg/yr.

Binary neutron star merger rate estimated at 22.77 Myr^{-1} in the Milky Way.

Abstract

We summarize the current state of the art and calculate gravitational wave strain amplitudes for known binary pulsars, using data from current ground-based detectors (LIGO-Virgo-KAGRA) and the upcoming space-based missions (LISA). We present detailed calculations of the characteristic gravitational wave strain values, ranging from 3.0 to 73 $\times10^{-22}$, across frequencies between 0.66 and 5.87 $\times10^{-4}$ Hz. Our post-Newtonian approximation analysis yields predicted periastron advance rates from 1.6 to 80.5 deg/yr and orbital period decay rates between -5 and -176 $\mu$s/yr for the binary pulsar population. We derive common envelope efficiency parameters ($\alpha_{CE}$) for representative progenitor scenarios within our sample, finding values between 0.63 and 1.16, with notable sensitivity to the binding energy parameter $\lambda$. Binary neutron star merger rates are estimated at $22.77^{+6.83}_{-6.83}$ Myr$^{-1}$ for the Milky Way, corresponding to a volumetric rate of $227.71^{+68.31}_{-68.31}$ Gpc$^{-3}$ yr$^{-1}$, consistent with the latest LIGO-Virgo-KAGRA observational constraints. Our results illustrate how multi-band gravitational wave observations, from LIGO/Virgo to LISA, can contribute to precise measurements of binary pulsar strain and orbital evolution histories, improving merger time predictions and constraining neutron star physics and common envelope processes