2019/07/10 by G. Sigl, Sigl, Günter, Pranjal Trivedi +1 · 1 citation
Physics and Astronomy · #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #High Energy Astrophysical Phenomena (astro-ph.HE) #Scientific Research and Discoveries
paper · pdf · doi:10.48550/arxiv.1907.04849
openalex publication_date 2019/07/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We investigate the possible parametric growth of photon amplitudes in a background of axion-like particle (ALP) dark matter. The observed extragalactic background radiation limits the allowed enhancement effect. We derive the resulting constraints on the axion-photon coupling constant gaγ from Galactic ALP condensates as well as over-densities. If ALP condensates of size R exist in our Galaxy, a scan for extremely narrow unresolved spectral lines with frequency ν can constrain the axion-photon coupling at ALP mass ma=4πν to gaγ\lesssim2×10-14(10 \rm kpc/R) \rm GeV-1. Radio to optical background data yield constraints at this level within observed wavebands or ALP mass windows over a broad range 0.08 μeV \lesssim ma \lesssim 8 eV. These condensate constraints on gaγ probe down to the QCD axion band for ma \gtrsim 10 μeV.