Angular correlation as a novel probe of supermassive primordial black holes

TL;DR

This paper explores the angular correlation of primordial black holes as a new method to test their role in forming supermassive black holes, highlighting the high clustering which may challenge such models.

Contribution

It introduces a novel approach using angular correlation functions of PBHs from spectator field fluctuations to evaluate their viability as SMBH progenitors.

Findings

PBHs exhibit high spatial clustering in this scenario.

Clustering properties can serve as a critical test for PBH-origin SMBH models.

Models with highly clustered PBHs may be disfavored by SMBH observations.

Abstract

We investigate the clustering property of primordial black holes (PBHs) in a scenario where PBHs can explain the existence of supermassive black holes (SMBHs) at high redshifts. We analyze the angular correlation function of PBHs originating from fluctuations of a spectator field which can be regarded as a representative model to explain SMBHs without conflicting with the constraint from the spectral distortion of cosmic microwave background. We argue that the clustering property of PBHs can give a critical test for models with PBHs as the origin of SMBHs and indeed show that the spatial distribution of PBHs in such a scenario is highly clustered, which suggests that those models may be disfavored from observations of SMBHs although a careful comparison with observational data would be necessary.