Novel Solar System Probes for Primordial Black Holes

TL;DR

The paper proposes Solar System–scale probes as local tests of primordial black holes (PBHs) as dark matter, developing two complementary channels: (i) pulsar timing array (PTA) based dipolar signatures from asteroid-mass PBHs altering the Solar System barycenter, and (ii) ADAF-powered optical flares from planetary-mass PBHs interacting with outer Solar System bodies. It derives the relevant scalings for kicks, strains, accretion-driven luminosities, and detectability distances, and provides forecasted limits and event rates under plausible parameters. Although current PTA sensitivity does not yet reach the local dark matter density, the framework offers a time-resolved, local laboratory for PBH phenomenology that probes mass windows largely inaccessible to cosmological probes. With longer time baselines and upcoming wide-field surveys, these Solar System probes could tighten PBH dark matter constraints or reveal nearby PBHs, offering a valuable, independent check on early-Universe PBH scenarios.

Abstract

Primordial Black Holes (PBHs) represent one of the more interesting ways to address dark matter, at the interface of both cosmology and quantum gravity. It is no surprise then that testing PBHs is a venue of active interest, with several cosmological and astrophysical probes constraining different mass ranges. In this work, we propose novel Solar System scale searches for PBHs, motivated by the unique precision and coverage of local observables. We show that asteroid to dwarf planet mass PBHs can induce measurable dipolar timing signatures in pulsar timing arrays, while planetary mass PBHs can generate detectable ADAF accretion flares through interactions with Kuiper Belt bodies. Together, these complementary approaches open a new observational frontier for probing PBHs across mass ranges that remain unconstrained by conventional cosmological methods.