2020/12/31 by Jacopo Fumagalli, Sébastien Renaux‐Petel, Sébastien Renaux-Petel +1
Earth and Planetary Sciences · Physics and Astronomy · #Astrophysics #Classical mechanics #Cosmology and Gravitation Theories #Geophysics and Gravity Measurements #Gravitation #Gravitational wave #Gravitational wave background #Inflation (cosmology) #Observable #Oscillation (cell signaling) #Physics #Pulsars and Gravitational Waves Research #Quantum electrodynamics #Quantum mechanics #Scalar (mathematics) #Spectral density #Statistical physics #Statistics #Theoretical physics #astro-ph.CO #hep-th
paper · pdf · doi:10.1088/1475-7516/2021/08/030
published as JCAP 08 (2021) 030 · 46 pages, 11 figures; v2: expanded the discussion of observational prospects as well as of resonant features, references added; v3: version published in JCAP, typos corrected
openalex created_date 2020/12/21 · openalex publication_date 2021/08/01 · arxiv created 2021/09/23 · arxiv updated 2021/09/24 · openalex updated_date 2026/08/05
We identify a characteristic pattern in the scalar-induced stochastic gravitational wave background from particle production during inflation. If particle production is sufficiently efficient, the scalar power spectrum exhibits (1) oscillations periodic in k , characteristic of a sharp feature, with an exponentially enhanced envelope. We systematically study the properties of the induced spectrum of gravitational waves sourced after inflation and find that this inherits the periodic structure in k , resulting in a peak in the gravitational wave energy density spectrum with (10 %) modulations. The frequency of the oscillation in the scalar power spectrum is determined by the scale of the feature during inflation and in turn sets the frequency of modulations in the gravitational wave signal. We present an explicit realisation of this phenomenon in the framework of multifield inflation, in the form of a strong sharp turn in the inflationary trajectory. The resulting stochastic background is potentially detectable in future gravitational wave observatories, and considerations of backreaction and perturbativity can be used to constrain the parameter space from the theoretical side. Our work motivates more extensive research linking primordial features to observable properties of the stochastic background of gravitational waves, and dedicated development in data analysis for their detection.