TY - JOUR
T1 - Running spectral index from inflation with modulations
AU - Kobayashi, Takeshi
AU - Takahashi, Fuminobu
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2011/1
Y1 - 2011/1
N2 - We argue that a large negative running spectral index, if confirmed, might suggest that there are abundant structures in the inflaton potential, which result in a fairly large (both positive and negative) running of the spectral index at all scales. It is shown that the center value of the running spectral index suggested by the recent CMB data can be easily explained by an inflaton potential with superimposed periodic oscillations. In contrast to cases with constant running, the perturbation spectrum is enhanced at small scales, due to the repeated modulations. We mention that such features at small scales may be seen by 21 cm observations in the future.
AB - We argue that a large negative running spectral index, if confirmed, might suggest that there are abundant structures in the inflaton potential, which result in a fairly large (both positive and negative) running of the spectral index at all scales. It is shown that the center value of the running spectral index suggested by the recent CMB data can be easily explained by an inflaton potential with superimposed periodic oscillations. In contrast to cases with constant running, the perturbation spectrum is enhanced at small scales, due to the repeated modulations. We mention that such features at small scales may be seen by 21 cm observations in the future.
KW - Cosmological parameters from CMBR
KW - Inflation
KW - Physics of the early universe
KW - Power spectrum
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U2 - 10.1088/1475-7516/2011/01/026
DO - 10.1088/1475-7516/2011/01/026
M3 - Article
AN - SCOPUS:79551672847
VL - 2011
JO - Journal of Cosmology and Astroparticle Physics
JF - Journal of Cosmology and Astroparticle Physics
SN - 1475-7516
IS - 1
M1 - 026
ER -