Multibanded Reduced Order Quadrature Techniques for Gravitational Wave Inference

TL;DR

This paper introduces a multibanded approach to constructing reduced-order quadrature bases for gravitational wave parameter estimation, significantly reducing computational costs while maintaining accuracy.

Contribution

It presents a modified basis construction method using multiband waveforms that accelerates ROQ basis creation without sacrificing likelihood precision.

Findings

Basis size reduced by 20-30%.

Construction time decreased by 5-20 times, from two weeks to days.

Parameter estimation results remain consistent with standard methods.

Abstract

Reduced-order quadrature (ROQ) is commonly used to accelerate parameter estimation in gravitational wave astronomy; however, constructing ROQ bases can be computationally costly, particularly for longer-duration signals. We propose a modified construction strategy based on PyROQ that accelerates this process by performing the basis search using multiband waveforms, without compromising the desired likelihood accuracy. We use this altered method to construct a set of ROQs in the sub-solar mass (SSM) range using the IMRPhenomXAS_NRTidalV3 waveform. Compared to PyROQ's standard ROQ method, we find a decrease in basis size of 20% to 30% and observe a decrease in basis construction time by 5 to 20 times, reducing from two weeks to a couple of days. We verify the bases built with this method by injecting simulated gravitational waves into LIGO-Virgo-KAGRA design noise and recovering the parameters, and we find that they preserve the likelihood accuracy and maintain consistent parameter estimation results.