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Title: Accidental Kähler moduli inflation

Abstract

We study a model of accidental inflation in type IIB string theory where inflation occurs near the inflection point of a small Kähler modulus. A racetrack structure helps to alleviate the known concern that string-loop corrections may spoil Kähler Moduli Inflation unless having a significant suppression via the string coupling or a special brane setup. Also, the hierarchy of gauge group ranks required for the separation between moduli stabilization and inflationary dynamics is relaxed. The relaxation becomes more significant when we use the recently proposed D-term generated racetrack model.

Authors:
 [1];  [2];  [3]
  1. Harish Chandra Research Institute,Chhatnag Road, Jhunsi, Allahabad, UP 211019 (India)
  2. Rudolph Peierls Centre for Theoretical Physics, University of Oxford,1 Keble Road, Oxford, OX1 3NP (United Kingdom)
  3. High Energy Accelerator Research Organization, KEK,1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)
Publication Date:
Sponsoring Org.:
SCOAP3, CERN, Geneva (Switzerland)
OSTI Identifier:
22458377
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2015; Journal Issue: 09; Other Information: PUBLISHER-ID: JCAP09(2015)040; OAI: oai:repo.scoap3.org:11803; Article funded by SCOAP3. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 License. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; BRANES; CORRECTIONS; COSMOLOGICAL INFLATION; RELAXATION; STRING MODELS

Citation Formats

Maharana, Anshuman, Rummel, Markus, and Sumitomo, Yoske. Accidental Kähler moduli inflation. United States: N. p., 2015. Web. doi:10.1088/1475-7516/2015/09/040.
Maharana, Anshuman, Rummel, Markus, & Sumitomo, Yoske. Accidental Kähler moduli inflation. United States. doi:10.1088/1475-7516/2015/09/040.
Maharana, Anshuman, Rummel, Markus, and Sumitomo, Yoske. 2015. "Accidental Kähler moduli inflation". United States. doi:10.1088/1475-7516/2015/09/040.
@article{osti_22458377,
title = {Accidental Kähler moduli inflation},
author = {Maharana, Anshuman and Rummel, Markus and Sumitomo, Yoske},
abstractNote = {We study a model of accidental inflation in type IIB string theory where inflation occurs near the inflection point of a small Kähler modulus. A racetrack structure helps to alleviate the known concern that string-loop corrections may spoil Kähler Moduli Inflation unless having a significant suppression via the string coupling or a special brane setup. Also, the hierarchy of gauge group ranks required for the separation between moduli stabilization and inflationary dynamics is relaxed. The relaxation becomes more significant when we use the recently proposed D-term generated racetrack model.},
doi = {10.1088/1475-7516/2015/09/040},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 09,
volume = 2015,
place = {United States},
year = 2015,
month = 9
}
  • We study a model of accidental inflation in type IIB string theory where inflation occurs near the inflection point of a small Kähler modulus. A racetrack structure helps to alleviate the known concern that string-loop corrections may spoil Kähler Moduli Inflation unless having a significant suppression via the string coupling or a special brane setup. Also, the hierarchy of gauge group ranks required for the separation between moduli stabilization and inflationary dynamics is relaxed. The relaxation becomes more significant when we use the recently proposed D-term generated racetrack model.
  • We analyze the possibility of realizing inflation with a subsequent dS vacuum in the Käahler uplifting scenario. The inclusion of several quantum corrections to the 4d effective action evades previous no-go theorems and allows for construction of simple and successful models of string inflation. The predictions of several benchmark models are in accord with current observations, i.e., a red spectral index, negligible non-gaussianity, and spectral distortions similar to the simplest models of inflation. A particularly interesting subclass of models are ''left-rolling'' ones, where the overall volume of the compactified dimensions shrinks during inflation. We call this phenomenon ''inflation by deflation''more » (IBD), where deflation refers to the internal manifold. This subclass has the appealing features of being insensitive to initial conditions, avoiding the overshooting problem, and allowing for observable running α ∼ 0.012 and enhanced tensor-to-scalar ratio r ∼ 10{sup −5}. The latter results differ significantly from many string inflation models.« less
  • We show that double inflation is naturally realized in Kähler moduli inflation, which is caused by moduli associated with string compactification. We find that there is a small coupling between the two inflatons which leads to amplification of perturbations through parametric resonance in the intermediate stage of double inflation. This results in the appearance of a peak in the power spectrum of the primordial curvature perturbation. We numerically calculate the power spectrum and show that the power spectrum can have a peak on observationally interesing scales. We also compute the TT-spectrum of CMB based on the power spectrum with amore » peak and see that it better fits WMAP 7-years data.« less
  • We assess which Kähler potentials in supergravity lead to viable single-field inflationary models that are consistent with Planck. We highlight the role of symmetries, such as shift, Heisenberg and supersymmetry, in these constructions. Also the connections to string theory are pointed out. Finally, we discuss a supergravity model for arbitrary inflationary potentials that is suitable for open string inflation and generalise it to the case of closed string inflation. Our model includes the recently discussed supergravity reformulation of the Starobinsky model of inflation as well as an interesting alternative with comparable predictions.
  • We present a novel realization of Starobinsky-type inflation within Supergravity using two chiral superfields. The proposed superpotential is inspired by induced-gravity models. The Kähler potential contains two logarithmic terms, one for the inflaton T and one for the matter-like field S, parameterizing the SU(1,1)/U(1)×SU(2)/U(1) Kähler manifold. The two factors have constant curvatures −m/n and 2/n{sub 2}, where n, m are the exponents of T in the superpotential and Kähler potential respectively, and 0