Projected constraints on the abundance of primordial black holes from LISA for a broad primordial spectrum

Abstract

In this paper, we briefly report the minimum projected PBH abundance f_PBH constraints for the future LISA GW detector for PBHs generated from primordial fluctuations with a broad power spectrum. We use the IMRPhenomXAS waveform model to capture the range of mass ratios up to q = 1000, and use our existing constraining methodology to obtain the f_PBH constraint curves for monochromatic and power law PBH population distributions. Our results suggest that incorporating higher mass ratios into the calculation raises the required minimum abundances in order to achieve a detectable event signal for broad mass functions, resulting in minimum abundances higher by an order of magnitude or greater relative to the monochromatic case.