2021/05/19 by Isaac Wong, Isaac C. F. Wong, Wong, Isaac C. F. +10 · 1 citation
Earth and Planetary Sciences · Mathematics · Physics and Astronomy · #Astrophysical Phenomena and Observations #Cosmology and Gravitation Theories #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #Geophysics and Gravity Measurements #High Energy Astrophysical Phenomena (astro-ph.HE) #Pulsars and Gravitational Waves Research #Statistical and numerical algorithms #astro-ph.HE #gr-qc
paper · pdf · doi:10.48550/arxiv.2105.09485
26 pages, 20 figures
openalex publication_date 2021/05/20 · arxiv created 2021/06/05 · arxiv updated 2021/06/08 · openalex created_date 2022/07/25 · openalex updated_date 2026/07/28
We present a null-stream-based Bayesian unmodeled framework to probe generic gravitational-wave polarizations. Generic metric theories allow six gravitational-wave polarization states, but general relativity only permits the existence of two of them namely the tensorial polarizations. The strain signal measured by an interferometer is a linear combination of the polarization modes and such a linear combination depends on the geometry of the detector and the source location. The detector network of Advanced LIGO and Advanced Virgo allows us to measure different linear combinations of the polarization modes and therefore we can constrain the polarization content by analyzing how the polarization modes are linearly combined. We propose the basis formulation to construct a null stream along the polarization basis modes without requiring modeling the basis explicitly. We conduct a mock data study and we show that the framework is capable of probing pure and mixed polarizations in the Advanced LIGO-Advanced Virgo 3-detector network without knowing the sky location of the source from electromagnetic counterparts. We also discuss the effect of the presence of the uncaptured orthogonal polarization component in the framework, and we propose using the plug-in method to test the existence of the orthogonal polarizations.