In the modulated reheating scenario, the field that drives inflation has a spatially varying decay rate, and the resulting inhomogeneous reheating process generates adiabatic perturbations. We examine the statistical properties of the density perturbations generated in this scenario. Unlike earlier analyses, we include the dynamics of the field that determines the inflaton decay rate. We show that the dynamics of this modulus field can significantly alter the amplitude of the power spectrum and the bispectrum, even if the modulus field has a simple potential and its effective mass is smaller than the Hubble rate. In some cases, the evolution of the modulus amplifies the non-Gaussianity of the perturbations to levels that are excluded by recent observations of the cosmic microwave background. Therefore, a proper treatment of the modulus dynamics is required to accurately calculate the statistical properties of the perturbations generated by modulated reheating. © 2014 IOP Publishing Ltd and Sissa Medialab srl.
Rolling in the modulated reheating scenario / Kobayashi, N.; Kobayashi, T.; Erickcek, A. L.. - In: JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS. - ISSN 1475-7516. - 2014:1(2014), pp. 1-26. [10.1088/1475-7516/2014/01/036]
Rolling in the modulated reheating scenario
Kobayashi T.
;
2014-01-01
Abstract
In the modulated reheating scenario, the field that drives inflation has a spatially varying decay rate, and the resulting inhomogeneous reheating process generates adiabatic perturbations. We examine the statistical properties of the density perturbations generated in this scenario. Unlike earlier analyses, we include the dynamics of the field that determines the inflaton decay rate. We show that the dynamics of this modulus field can significantly alter the amplitude of the power spectrum and the bispectrum, even if the modulus field has a simple potential and its effective mass is smaller than the Hubble rate. In some cases, the evolution of the modulus amplifies the non-Gaussianity of the perturbations to levels that are excluded by recent observations of the cosmic microwave background. Therefore, a proper treatment of the modulus dynamics is required to accurately calculate the statistical properties of the perturbations generated by modulated reheating. © 2014 IOP Publishing Ltd and Sissa Medialab srl.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.