Probing Primordial Black Hole Mergers in Clusters with Pulsar Timing Data
The study searched for a gravitational wave background from merging Primordial Black Holes (PBHs) using Pulsar Timing Array data. The results show that scalar-induced gravitational waves dominate this background under standard assumptions, meaning PBH mergers alone cannot explain the observed signal. Specific PBH models with enhanced clustering could potentially yield a merger-dominated signal.