Bound on largest r ∼< 0.1 from subPlanckian excursions of inflaton
Abstract
In this paper we will discuss the range of large tensor to scalar ratio, r, obtainable from a subPlanckian excursion of a single, slow roll driven inflaton field. In order to obtain a large r for such a scenario one has to depart from a monotonic evolution of the slow roll parameters in such a way that one still satisfies all the current constraints of \texttt(Planck), such as the scalar amplitude, the tilt in the scalar power spectrum, running and running of the tilt close to the pivot scale. Since the slow roll parameters evolve nonmonotonically, we will also consider the evolution of the power spectrum on the smallest scales, i.e. at P{sub s}(k ∼ 10{sup 16} Mpc{sup −1})∼< 10{sup −2}, to make sure that the amplitude does not become too large. All these constraints tend to keep the tensor to scalar ratio, r ∼< 0.1. We scan three different kinds of potential for supersymmetric flat directions and obtain the benchmark points which satisfy all the constraints. We also show that it is possible to go beyond r ∼> 0.1 provided we relax the upper bound on the power spectrum on the smallest scales.
 Authors:
 HarishChandra Research Institute, Chhatnag Road, Jhusi, Allahabad, 211 019 (India)
 Physics Department, Lancaster University, Bailrigg, Lancaster, LA1 4YB (United Kingdom)
 Publication Date:
 OSTI Identifier:
 22382017
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2015; Journal Issue: 01; Other Information: Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; AMPLITUDES; EVOLUTION; EXCURSIONS; LIMITING VALUES; POTENTIALS; SCALARS; SPECTRA; SUPERSYMMETRY; TENSORS
Citation Formats
Chatterjee, Arindam, and Mazumdar, Anupam, Email: arindam@hri.res.in, Email: a.mazumdar@lancaster.ac.uk. Bound on largest r ∼< 0.1 from subPlanckian excursions of inflaton. United States: N. p., 2015.
Web. doi:10.1088/14757516/2015/01/031.
Chatterjee, Arindam, & Mazumdar, Anupam, Email: arindam@hri.res.in, Email: a.mazumdar@lancaster.ac.uk. Bound on largest r ∼< 0.1 from subPlanckian excursions of inflaton. United States. doi:10.1088/14757516/2015/01/031.
Chatterjee, Arindam, and Mazumdar, Anupam, Email: arindam@hri.res.in, Email: a.mazumdar@lancaster.ac.uk. 2015.
"Bound on largest r ∼< 0.1 from subPlanckian excursions of inflaton". United States.
doi:10.1088/14757516/2015/01/031.
@article{osti_22382017,
title = {Bound on largest r ∼< 0.1 from subPlanckian excursions of inflaton},
author = {Chatterjee, Arindam and Mazumdar, Anupam, Email: arindam@hri.res.in, Email: a.mazumdar@lancaster.ac.uk},
abstractNote = {In this paper we will discuss the range of large tensor to scalar ratio, r, obtainable from a subPlanckian excursion of a single, slow roll driven inflaton field. In order to obtain a large r for such a scenario one has to depart from a monotonic evolution of the slow roll parameters in such a way that one still satisfies all the current constraints of \texttt(Planck), such as the scalar amplitude, the tilt in the scalar power spectrum, running and running of the tilt close to the pivot scale. Since the slow roll parameters evolve nonmonotonically, we will also consider the evolution of the power spectrum on the smallest scales, i.e. at P{sub s}(k ∼ 10{sup 16} Mpc{sup −1})∼< 10{sup −2}, to make sure that the amplitude does not become too large. All these constraints tend to keep the tensor to scalar ratio, r ∼< 0.1. We scan three different kinds of potential for supersymmetric flat directions and obtain the benchmark points which satisfy all the constraints. We also show that it is possible to go beyond r ∼> 0.1 provided we relax the upper bound on the power spectrum on the smallest scales.},
doi = {10.1088/14757516/2015/01/031},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 01,
volume = 2015,
place = {United States},
year = 2015,
month = 1
}

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