New mechanism for primordial black hole formation from the QCD axion

Abstract

We present a new mechanism for the primordial black hole (PBH) production within the QCD axion framework. We take the case where the Peccei-Quinn symmetry breaks during inflation, resulting in a $N_{\mathrm{DW}}=1$ string-wall network that re-enters horizon sufficiently late. Therefore, closed axion domain walls naturally arising in the network are sufficiently large to collapse into PBHs. Our numerical simulation shows that $\sim 0.3\%$ of the total wall area is in the form of closed walls. In addition, the relic abundance of dark matter is dominantly accounted for by free axions from the collapse of open walls bounded by strings. In this framework, the abundance of PBH within dark matter is calculated to be $\sim 0.9\%$. This fraction remains unaffected by axion parameters or the re-entering horizon temperature, as it is determined by the fixed proportion of closed walls in the network, governed by the principles of percolation theory. The resultant PBHs uniformly share the same mass, which spans from about $10^{-9}$ to $1$ solar mass, corresponding to the classical QCD axion mass window $10^{-5}-10^{-2}$~eV and the re-entering horizon temperature $300-1$~MeV. Intriguingly, PBHs in this mechanism can naturally account for the ultrashort-timescale gravitational microlensing events observed by the OGLE collaboration.

arXiv comment8 pages, 4 figures. Match the published version

References in corpus (42)

• Axion Cosmology
• Limits on the Macho Content of the Galactic Halo from the EROS-2 Survey of the Magellanic Clouds
• The landscape of QCD axion models
• MeV-scale Reheating Temperature and Thermalization of Neutrino Background
• Microlensing constraints on primordial black holes with the Subaru/HSC Andromeda observation
• Supernova 1987A Constraints on Sub-GeV Dark Sectors, Millicharged Particles, the QCD Axion, and an Axion-like Particle
• Constraints on Earth-mass primordial black holes from OGLE 5-year microlensing events
• Cosmological Constraints on Late-time Entropy Production
• Axion dark matter from topological defects
• No large population of unbound or wide-orbit Jupiter-mass planets
• MeV-scale reheating temperature and thermalization of oscillating neutrinos by radiative and hadronic decays of massive particles
• Axions from Strings: the Attractive Solution
• More Axions from Strings
• Early-Universe Simulations of the Cosmological Axion
• Production of dark matter axions from collapse of string-wall systems
• Improved axion emissivity from a supernova via nucleon-nucleon bremsstrahlung
• Early seeds of axion miniclusters
• The dark-matter axion mass
• Studies of the motion and decay of axion walls bounded by strings
• Axion cosmology with long-lived domain walls
• Primordial black hole and wormhole formation by domain walls
• Gravitational Waves from Collapsing Domain Walls
• Axion dark matter: strings and their cores
• Science with the TianQin observatory: Preliminary results on stellar-mass binary black holes
• The art of simulating the early Universe -- Part I
• What if Planet 9 is a Primordial Black Hole?
• Primordial Black Holes from the QCD axion
• Evolution of String-Wall Networks and Axionic Domain Wall Problem
• Confronting the primordial black hole scenario with the gravitational-wave events detected by LIGO-Virgo
• How to simulate global cosmic strings with large string tension
• Probing planetary-mass primordial black holes with continuous gravitational waves
• Suppressing Isocurvature Perturbations of QCD Axion Dark Matter
• Dynamics of Peccei-Quinn Breaking Field after Inflation and Axion Isocurvature Perturbations
• Primordial Black Holes from QCD Axion Bubbles
• The meso-inflationary QCD axion
• Gravitational Waves from an Inflation Triggered First-Order Phase Transition
• High-Scale Axions without Isocurvature from Inflationary Dynamics
• Sublunar-Mass Primordial Black Holes from Closed Axion Domain Walls
• Do Global String Loops Collapse to Form Black Holes?
• Searching for Black Holes in the Outer Solar System with LSST
• Opening up a window on the postinflationary QCD axion
• Tracing Astrophysical Black Hole Seeds and Primordial Black Holes with LISA-Taiji Network

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• Cosmological Consequences of Domain Walls Biased by Quantum Gravity
• Meso-inflationary Peccei-Quinn symmetry breaking with non-minimal coupling
• Gravitational Wave Mountains: current-carrying domain walls
• The Dark Side of the Moon: Listening to Scalar-Induced Gravitational Waves