2016/04/30 by Yohei Ema, Ryusuke Jinno, Kyohei Mukaida +1 · 158 citations
Physics and Astronomy · #Astrophysics #Axion #Classical mechanics #Cosmology #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark energy #Dark matter #Galaxies: Formation, Evolution, Phenomena #Gravitation #Gravitational field #Hubble's law #Inflation (cosmology) #Metric expansion of space #Oscillation (cell signaling) #Particle physics #Physics #Scalar field #Scale factor (cosmology) #Theoretical physics #Universe #astro-ph.CO #gr-qc #hep-ph
paper · pdf · doi:10.1103/physrevd.94.063517
published in Physical review. D/Physical review. D. 94(6), 63517 (American Physical Society) · 1+35 pages, 3 figures; v2: references added, version accepted in PRD; v3: references corrected
openalex created_date 2016/06/24 · openalex publication_date 2016/09/14 · arxiv created 2016/10/04 · arxiv updated 2016/10/05 · openalex updated_date 2026/08/05
We study the production of light particles due to the oscillation of the Hubble parameter or the scale factor. Any coherently oscillating scalar field, irrespective of its energy fraction in the Universe, imprints such an oscillating feature on them. Not only Einstein gravity but the extended gravity models, such as models with nonminimal (derivative) coupling to gravity and f(R) gravity, lead to oscillation of the scale factor. We present a convenient way to estimate the gravitational particle production rate in these circumstances. Cosmological implications of gravitational particle production, such as dark matter/radiation and moduli problem, are discussed. For example, if the theory is described solely by the standard model plus the Peccei-Quinn sector, the Starobinsky R2 inflation may lead to an observable amount of axion dark radiation.