Measuring the maximally allowed polarization states of the isotropic stochastic gravitational wave background with the ground-based detectors

Understand

We discuss the polarizational study of isotropic gravitational wave backgrounds with the second generation detector network, paying special attention to the impacts of adding LIGO-India.

• The backgrounds can be characterized by at most five spectral components (three parity-even ones and two parity-odd ones).
• They can be algebraically decomposed through the difference of the corresponding overlap reduction functions defined for the individual spectra.
• We newly identify two interesting relations between the overlap reduction functions, and these relations generally hamper the algebraic decomposition in the low frequency regime $f \lesssim 30$Hz.