Running spectral index from inflation with modulations

Journal Article · Sat Jan 01 00:00:00 EST 2011 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2011/01/026· OSTI ID:22275273

Kobayashi, Takeshi ^[1]; Takahashi, Fuminobu ^[2]

---

1. Institute for Cosmic Ray Research, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582 (Japan)
2. Institute for the Physics and Mathematics of the Universe, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan)

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.

• OSTI ID: 22275273
• Journal Information: Journal of Cosmology and Astroparticle Physics, Vol. 2011, Issue 01; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
COSMOLOGY
INDEXES
INFLATIONARY UNIVERSE
INFLATONS
MODULATION
OSCILLATIONS
PERIODICITY
PERTURBATION THEORY
POTENTIALS