Massively parallel Bayesian inference for transient gravitational-wave astronomy

Understanding the properties of transient gravitational waves (GWs) and their sources is of broad interest in physics and astronomy. Bayesian inference is the standard framework for astrophysical measurement in transient GW astronomy. Usually, stochastic sampling algorithms are used to estimate posterior probability distributions over the parameter spaces of models describing experimental data. The most physically accurate models typically come with a large computational overhead which can render data analsis extremely time consuming, or possibly even prohibitive. In some cases highly specialized optimizations can mitigate these issues, though they can be difficult to implement, as well as to generalize to arbitrary models of the data. Here, we investigate an accurate, flexible, and scalable method for astrophysical inference: parallelized nested sampling. The reduction in the wall-time of inference scales almost linearly with the number of parallel processes running on a high-performance computing cluster. By utilizing a pool of several hundreds or thousands of CPUs in a high-performance cluster, the large wall times of many astrophysical inferences can be alleviated while simultaneously ensuring that any GW signal model can be used 'out of the box', i.e. without additional optimization or approximation. Our method will be useful to both the LIGO-Virgo-KAGRA collaborations and the wider scientific community performing astrophysical analyses on GWs. An implementation is available in the open source gravitational-wave inference library pBilby (parallel bilby).

gravitational waves, methods: data analysis

10.1093/mnras/staa2483

0035-8711

4492-4502

Smith, Rory J.E.

2a8b78f9-6abf-4306-8a9d-10158e5b49a4

Ashton, Gregory

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Vajpeyi, Avi

dcfc1c1b-4991-4f51-9073-e543903f8118

Talbot, Colm

cc506291-608c-4a95-8e84-78a67954d79c

1 November 2020