Morphology-independent test of the mixed polarization content of transient gravitational wave signals

Gravitational waves in general relativity contain two polarization degrees of freedom, commonly labeled plus and cross. Besides those tensor modes, generic theories gravity predict up to four additional modes: scalar vector. Detection nontensorial modes gravitational wave data would constitute a clean signature physics beyond relativity. Previous measurements have pointed the unambiguous presence waves, but has not been directly tested. We propose model-independent analysis capable detecting characterizing mixed nontensor components transient signals, including from compact binary coalescences. This infrastructure can constrain or vector on top predicted by Our is morphology-independent (as it does rely waveform templates), phase-coherent, agnostic about source sky location. apply our GW190521 simulated demonstrate that placing upper limits strength when none are present, their morphology case positive detection. Tests content signal hinge an extended detector network, wherein each observes different linear combination modes. therefore anticipate will yield precise constraints coming years, as current ground-based detectors LIGO Hanford, Livingston, Virgo joined KAGRA India.