How to assess the primordial origin of single gravitational-wave events with mass, spin, eccentricity, and deformability measurements

Understand

A population of primordial black holes formed in the early Universe could contribute to at least a fraction of the black-hole merger events detectable by current and future gravitational-wave interferometers.

• With the ever-increasing number of detections, an important open problem is how to discriminate whether a given event is of primordial or astrophysical origin.
• We systematically present a comprehensive and interconnected list of discriminators that would allow us to rule out, or potentially claim, the primordial origin of a binary by measuring different parameters, including redshift, masses, spins, eccentricity, and tidal deformability.
• We estimate how accurately future detectors (such as the Einstein Telescope and LISA) could measure these quantities, and we quantify the constraining power of each discriminator for current interferometers.