Axion configurations around pulsars

Abstract

Axion-like particles lead to a plethora of new phenomena relating to compact astrophysical objects including stellar and black hole superradiance, axion stars and axion clusters. In this work, we investigate a new scenario in which macroscopic axion configurations are sourced by the electromagnetic fields of pulsars via the axion-photon coupling. We solve the inhomogeneous axion field equation with an explicit source term given by the electromagnetic fields of the pulsar in a rotating magnetic dipole approximation. We find that the axion profile either forms a localised boundstate or radiates as outgoing waves, depending on whether the pulsar frequency is smaller or greater than the axion mass, respectively. We derive the total mass of the scalar cloud generated around the pulsar, and the power loss for radiative solutions. We point out that it will be necessary to incorporate pulsar magnetosphere effects and their partial screening of the axion-photon interaction for a more accurate quantitative prediction. Finally, we suggest some observational signatures which should be investigated in future work.

30 pages, 5 figures

References in corpus (21)

• Discovering the QCD Axion with Black Holes and Gravitational Waves
• Dielectric Haloscopes: A New Way to Detect Axion Dark Matter
• Black holes as particle detectors: evolution of superradiant instabilities
• Dilute and dense axion stars
• Ab-initio pulsar magnetosphere: three-dimensional particle-in-cell simulations of oblique pulsars
• Particle acceleration in axisymmetric pulsar current sheets
• Electrodynamics of axisymmetric pulsar magnetosphere with electron-positron discharge: a numerical experiment
• Bosenova collapse of axion cloud around a rotating black hole
• The Quest for an Intermediate-Scale Accidental Axion and Further ALPs
• The radio telescope search for the resonant conversion of cold dark matter axions from the magnetized astrophysical sources
• Dielectric Haloscopes to Search for Axion Dark Matter: Theoretical Foundations
• Fast Radio Bursts and Axion Miniclusters
• Electrodynamics of pulsar magnetospheres
• Theory of pulsar magnetosphere and wind
• Multipolar electromagnetic fields around neutron stars: exact vacuum solutions and related properties
• Axion minicluster power spectrum and mass function
• Superradiance in stars
• Testing dissipative magnetosphere model light curves and spectra with FERMI pulsars
• Constraining Axion-Like-Particles with Hard X-ray Emission from Magnetars
• Axions and "Light Shining Through a Wall": A Detailed Theoretical Analysis
• Astrophysical Haloscopes

Cited by in corpus (15)

• Axionic instabilities and new black hole solutions
• Fast radio bursts from axion stars moving through pulsar magnetospheres
• Axion superradiance in rotating neutron stars
• The QCD Axion at Finite Density
• Radio Line Properties of Axion Dark Matter Conversion in Neutron Stars
• Runaway Relaxion from Finite Density
• Diluted Axion Star Collisions with Neutron Stars
• Superradiance in Stars: Non-equilibrium approach to damping of fields in stellar media
• On long range axion hairs for black holes
• Magnetic dynamo caused by axions in neutron stars
• Static axionlike dark matter clouds around magnetized rotating wormholes -- probe limit case
• Axion-like dark matter clouds around rotating black holes
• Dilaton generation in propagation of magnetic dipole waves of pulsar in a galactic magnetic field
• Axion sourcing in dense stellar matter via CP-violating couplings
• Superdense beaming of axion dark matter in the vicinity of the light cylinder of pulsars