ALP dark matter with non-periodic potentials: parametric resonance, halo formation and gravitational signatures

Abstract

Axion-like particles (ALPs) are leading candidates to explain the dark matter in the universe. Their production via the misalignment mechanism has been extensively studied for cosine potentials characteristic of pseudo-Nambu-Goldstone bosons. In this work we investigate ALPs with non-periodic potentials, which allow for large misalignment of the field from the minimum. As a result, the ALP can match the relic density of dark matter in a large part of the parameter space. Such potentials give rise to self-interactions which can trigger an exponential growth of fluctuations in the ALP field via parametric resonance, leading to the fragmentation of the field. We study these effects with both Floquet analysis and lattice simulations. Using the Press-Schechter formalism, we predict the halo mass function and halo spectrum arising from ALP dark matter. These halos can be dense enough to produce observable gravitational effects such as astrometric lensing, diffraction of gravitational wave signals from black hole mergers, photometric microlensing of highly magnified stars, perturbations of stars in the galactic disk or stellar streams. These effects would provide a probe of dark matter even if it does not couple to the Standard Model. They would not be observable for halos predicted for standard cold dark matter and for ALP dark matter in the standard misalignment mechanism. We determine the relevant regions of parameter space in the (ALP mass, decay constant)-plane and compare predictions in different axion fragmentation models.

50 pages and 22 figures in the main text, and 15 pages and 2 figures in appendices, v2: As published in JCAP

References in corpus (37)

• Array Programming with NumPy
• Advanced LIGO
• Ultralight scalars as cosmological dark matter
• Laser Interferometer Space Antenna
• Cosmic Structure as the Quantum Interference of a Coherent Dark Wave
• Limits on the Macho Content of the Galactic Halo from the EROS-2 Survey of the Magellanic Clouds
• Monodromy in the CMB: Gravity Waves and String Inflation
• Understanding the Core-Halo Relation of Quantum Wave Dark Matter, $\psi$DM, from 3D Simulations
• Nonperturbative Dynamics Of Reheating After Inflation: A Review
• Detection of a 63 Degree Cold Stellar Stream in the Sloan Digital Sky Survey
• The Excursion Set Theory of Halo Mass Functions, Halo Clustering, and Halo Growth
• Lyman-alpha Constraints on Ultralight Scalar Dark Matter: Implications for the Early and Late Universe
• Pulsar Timing Probes of Primordial Black Holes and Subhalos
• Astrophysical Effects of Scalar Dark Matter Miniclusters
• Simulations of Axion Minihalos
• Axion minicluster power spectrum and mass function
• Approach to scaling in axion string networks
• Miniclusters in the Axiverse
• 3D simulations with boosted primordial power spectra and ultracompact minihalos
• Probing Small-Scale Power Spectra with Pulsar Timing Arrays
• Theia: Faint objects in motion or the new astrometry frontier
• Simulations of axion-like particles in the post-inflationary scenario
• Pure Natural Inflation
• Dark Matter Microhalos From Simplified Models
• Friendship in the Axiverse: Late-time direct and astrophysical signatures of early-time nonlinear axion dynamics
• Faint objects in motion: the new frontier of high precision astrometry
• Recipes for Oscillon Longevity
• Audible Axions with a Booster: Stochastic Gravitational Waves from Rotating ALPs
• Bayesian Forecasts for Dark Matter Substructure Searches with Mock Pulsar Timing Data
• ALP Dark Matter Mini-Clusters from Kinetic Fragmentation
• Nonperturbative structure in coupled axion sectors and implications for direct detection
• QCD Axion Kinetic Misalignment without Prejudice
• New scenario of QCD axion clump formation I: Linear analysis
• Resonant excitation of the axion field during the QCD phase transition
• One-parametric description for scalar field dark matter potentials
• Disruption of Dark Matter Minihaloes in the Milky Way environment: Implications for Axion Miniclusters and Early Matter Domination
• A lower bound on dark matter mass

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