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arXiv · 1404.5230

Fractional chaotic inflation in the lights of PLANCK and BICEP2

Xin Gao·Tianjun Li·Pramod Shukla
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Abstract

In the lights of current BICEP2 observations accompanied with the PLANCK satellite results, it has been observed that the simple single field chaotic inflationary models provide a good agreement with their spectral index n_s and large tensor-to-scalar ratio r (0.15 <r <0.26). To explore the other simple models, we consider the fractional-chaotic inflationary potentials of the form V_0 phi^(a/b) where a and b are relatively prime. We show that such kind of inflaton potentials can be realized elegantly in the supergravity framework with generalized shift symmetry and a nature bound a/b < 4 for consistency. Especially, for the number of e-folding from 50 to 60 and some a/b from 2 to 3, our predictions are nicely within at least 1 $σ$ region in the r-n_s plane. We also present a systematic investigation of such chaotic inflationary models with fractional exponents to explore the possibilities for the enhancement in the magnitude of running of spectral index (α_{n_s}) beyond the simplistic models.

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Xin Gao, Tianjun Li, Pramod Shukla. 2014-10-17. Fractional chaotic inflation in the lights of PLANCK and BICEP2. https://doi.org/10.1016/j.physletb.2014.10.007

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