TY - EJOUR AU - Domcke, Valerie AU - Guidetti, Veronica AU - Welling, Yvette AU - Westphal, Alexander TI - Resonant backreaction in axion inflation IS - arXiv:2002.02952 M1 - PUBDB-2020-00857 M1 - arXiv:2002.02952 M1 - DESY-20-017 PY - 2020 N1 - LaTeX, 1+28 pages, 10 figures AB - Axion inflation entails a coupling of the inflaton field to gauge fields through the Chern-Simons term. This results in a strong gauge field production during inflation, which backreacts on the inflaton equation of motion. Here we show that this strongly non-linear system generically experiences a resonant enhancement of the gauge field production, resulting in oscillatory features in the inflaton velocity as well as in the gauge field spectrum. The gauge fields source a strongly enhanced scalar power spectrum at small scales, exceeding previous estimates. For appropriate parameter choices, the collapse of these over-dense regions can lead to a large population of (light) primordial black holes with remarkable phenomenological consequences. KW - inflaton: field equations (autogen) KW - inflaton: coupling (autogen) KW - black hole: primordial (autogen) KW - power spectrum: scalar (autogen) KW - resonance: enhancement (autogen) KW - gauge field theory (autogen) KW - inflation (autogen) KW - axion (autogen) KW - Chern-Simons term (autogen) KW - back reaction (autogen) KW - nonlinear (autogen) KW - collapse (autogen) KW - velocity (autogen) LB - PUB:(DE-HGF)25 DO - DOI:10.3204/PUBDB-2020-00857 UR - https://bib-pubdb1.desy.de/record/435943 ER -