Large-scale curvature perturbations with spatial and time variations of the inflaton decay rate

  title={Large-scale curvature perturbations with spatial and time variations of the inflaton decay rate},
  author={S. Matarrese and Antonio Walter Riotto},
  journal={Journal of Cosmology and Astroparticle Physics},
We present a gauge-invariant formalism to study the evolution of the curvature and entropy perturbations in the case in which spatial and time variations of the inflaton decay rate into ordinary matter are present. During the reheating stage after inflation, curvature perturbations can vary with time on super-horizon scales sourced by a gauge-invariant inflaton decay rate perturbation. We show that the latter is a function not only of the spatial variations of the decay rate generated during… 
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  • Mollerach
  • Physics, Medicine
    Physical review. D, Particles and fields
  • 1990
It is found that the resulting fluctuations are not of the isocurvature type, but that the entropy perturbation induces a curvature fluctuation which is larger than the entropic one before the wavelengths of the perturbations enter the Hubble radius.