Pulsar-timing measurement of the circular polarization of the stochastic gravitational-wave background

Understand

Pulsar-timing arrays (PTAs) are in the near future expected to detect a stochastic gravitational-wave background (SGWB) produced by a population of inspiralling super-massive black hole binaries.

• In this work, we consider a background that can be anisotropic and circularly polarized.
• We use the expansion of the intensity and the circular polarization in terms of spherical harmonics and the overlap reduction functions for each term in this expansion.
• We propose an unbiased real-space estimator that can separate the intensity and circular-polarization contributions of the SGWB to pulsar-timing-residual correlations and then validate the estimator on simulated data.