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arXiv · 2504.16959

On Validating Angular Power Spectral Models for the Stochastic Gravitational-Wave Background Without Distributional Assumptions

Xiangyu Zhang·Erik Floden·Hongru Zhao·Sara Algeri·Galin Jones·Vuk Mandic·Jesse Miller
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Abstract

It is demonstrated that estimators of the angular power spectrum commonly used for the stochastic gravitational-wave background (SGWB) lack a closed-form analytical expression for the likelihood function and, typically, cannot be accurately approximated by a Gaussian likelihood. Nevertheless, a robust statistical analysis can be performed to enable the estimation and testing of angular power spectral models for the SGWB without specifying distributional assumptions. Here, the technical aspects of the method are discussed in detail. Moreover, a new, consistent estimator for the covariance of the angular power spectrum is derived. The proposed approach is applied to data from the third observing run (O3) of Advanced LIGO and Advanced Virgo.

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Xiangyu Zhang, Erik Floden, Hongru Zhao, Sara Algeri, Galin Jones, Vuk Mandic, Jesse Miller. 2025-04-23. On Validating Angular Power Spectral Models for the Stochastic Gravitational-Wave Background Without Distributional Assumptions. https://doi.org/10.1103/gpgk-5wd1

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