More axions from strings

• DOI: 10.21468/scipostphys.10.2.050
• Publication Date: 2021-02-26T08:19:23Z
• Authors: Marco Gorghetto; Edward Hardy; Giovanni Villadoro
• Keywords: High Energy Physics - Theory; High Energy Physics - Phenomenology; High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th); Physics; QC1-999; 0103 physical sciences; FOS: Physical sciences; 01 natural sciences; Astrophysics - Cosmology and Nongalactic Astrophysics

We study the contribution to QCD axion dark matter abundance that is produced by string defects during so-called scaling regime. Clear evidence of violations found, most conservative extrapolation which strongly suggests a large number axions from strings. In this regime, nonlinearities at around scale are shown play an important role in determining final abundance. The overall result lower bound on mass post-inflationary scenario substantially stronger than naive one misalignment.