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Title: Symmetry breaking indication for supergravity inflation in light of the Planck 2015

Abstract

Supergravity (SUGRA) theories with exact global U(1) symmetry or shift symmetry in Kähler potential provide natural frameworks for inflation. However, quadratic inflation is disfavoured by the new results on primordial tensor fluctuations from the Planck Collaboration. To be consistent with the new Planck data, we point out that the explicit symmetry breaking is needed, and study these two SUGRA inflation in detail. For SUGRA inflation with global U(1) symmetry, the symmetry breaking term leads to a trigonometric modulation on inflaton potential. Coefficient of the U(1) symmetry breaking term is of order 10{sup −2}, which is sufficient large to improve the inflationary predictions while its higher order corrections are negligible. Such models predict sizeable tensor fluctuations and highly agree with the Planck results. In particular, the model with a linear U(1) symmetry breaking term predicts the tensor-to-scalar ratio around r∼0.01 and running spectral index α{sub s}∼−0.004, which comfortably fit with the Planck observations. For SUGRA inflation with breaking shift symmetry, the inflaton potential is modulated by an exponential factor. The modulated linear and quadratic models are consistent with the Planck observations. In both types of models the tensor-to-scalar ratio can be of order 10{sup −2}, which will be tested by themore » near future observations.« less

Authors:
 [1];  [2];  [3];  [3];  [4];  [5]
  1. State Key Laboratory of Theoretical Physics, and Kavli Institute for Theoretical Physics China (KITPC), Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China)
  2. (China)
  3. George P. and Cynthia W. Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, TX 77843 (United States)
  4. (HARC), Mitchell Campus, Woodlands, TX 77381 (United States)
  5. (Greece)
Publication Date:
Sponsoring Org.:
SCOAP3, CERN, Geneva (Switzerland)
OSTI Identifier:
22458369
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)006; OAI: oai:repo.scoap3.org:11629; 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; COSMOLOGICAL INFLATION; SCALAR FIELDS; SUPERGRAVITY; SUPERSYMMETRY; SYMMETRY BREAKING; TENSOR FIELDS; U-1 GROUPS

Citation Formats

Li, Tianjun, School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054, Li, Zhijin, Nanopoulos, Dimitri V., Astroparticle Physics Group, Houston Advanced Research Center, and Academy of Athens, Division of Natural Sciences, 28 Panepistimiou Avenue, Athens 10679. Symmetry breaking indication for supergravity inflation in light of the Planck 2015. United States: N. p., 2015. Web. doi:10.1088/1475-7516/2015/09/006.
Li, Tianjun, School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054, Li, Zhijin, Nanopoulos, Dimitri V., Astroparticle Physics Group, Houston Advanced Research Center, & Academy of Athens, Division of Natural Sciences, 28 Panepistimiou Avenue, Athens 10679. Symmetry breaking indication for supergravity inflation in light of the Planck 2015. United States. doi:10.1088/1475-7516/2015/09/006.
Li, Tianjun, School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054, Li, Zhijin, Nanopoulos, Dimitri V., Astroparticle Physics Group, Houston Advanced Research Center, and Academy of Athens, Division of Natural Sciences, 28 Panepistimiou Avenue, Athens 10679. 2015. "Symmetry breaking indication for supergravity inflation in light of the Planck 2015". United States. doi:10.1088/1475-7516/2015/09/006.
@article{osti_22458369,
title = {Symmetry breaking indication for supergravity inflation in light of the Planck 2015},
author = {Li, Tianjun and School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 and Li, Zhijin and Nanopoulos, Dimitri V. and Astroparticle Physics Group, Houston Advanced Research Center and Academy of Athens, Division of Natural Sciences, 28 Panepistimiou Avenue, Athens 10679},
abstractNote = {Supergravity (SUGRA) theories with exact global U(1) symmetry or shift symmetry in Kähler potential provide natural frameworks for inflation. However, quadratic inflation is disfavoured by the new results on primordial tensor fluctuations from the Planck Collaboration. To be consistent with the new Planck data, we point out that the explicit symmetry breaking is needed, and study these two SUGRA inflation in detail. For SUGRA inflation with global U(1) symmetry, the symmetry breaking term leads to a trigonometric modulation on inflaton potential. Coefficient of the U(1) symmetry breaking term is of order 10{sup −2}, which is sufficient large to improve the inflationary predictions while its higher order corrections are negligible. Such models predict sizeable tensor fluctuations and highly agree with the Planck results. In particular, the model with a linear U(1) symmetry breaking term predicts the tensor-to-scalar ratio around r∼0.01 and running spectral index α{sub s}∼−0.004, which comfortably fit with the Planck observations. For SUGRA inflation with breaking shift symmetry, the inflaton potential is modulated by an exponential factor. The modulated linear and quadratic models are consistent with the Planck observations. In both types of models the tensor-to-scalar ratio can be of order 10{sup −2}, which will be tested by the near future observations.},
doi = {10.1088/1475-7516/2015/09/006},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 09,
volume = 2015,
place = {United States},
year = 2015,
month = 9
}
  • Supergravity (SUGRA) theories with exact global U(1) symmetry or shift symmetry in Kähler potential provide natural frameworks for inflation. However, quadratic inflation is disfavoured by the new results on primordial tensor fluctuations from the Planck Collaboration. To be consistent with the new Planck data, we point out that the explicit symmetry breaking is needed, and study these two SUGRA inflation in detail. For SUGRA inflation with global U(1) symmetry, the symmetry breaking term leads to a trigonometric modulation on inflaton potential. Coefficient of the U(1) symmetry breaking term is of order 10{sup −2}, which is sufficient large to improve themore » inflationary predictions while its higher order corrections are negligible. Such models predict sizeable tensor fluctuations and highly agree with the Planck results. In particular, the model with a linear U(1) symmetry breaking term predicts the tensor-to-scalar ratio around r∼0.01 and running spectral index α{sub s∼} −0.004, which comfortably fit with the Planck observations. For SUGRA inflation with breaking shift symmetry, the inflaton potential is modulated by an exponential factor. The modulated linear and quadratic models are consistent with the Planck observations. In both types of models the tensor-to-scalar ratio can be of order 10{sup −2}, which will be tested by the near future observations.« less
  • In this work we consider a DBI Galileon (DBIG) inflationary model and constrain its parameter space with the Planck 2015 and BICEP2/Keck array and Planck (BKP) joint analysis data by means of a potential independent analysis. We focus our attention on inflationary solutions characterized by a constant or varying sound speed as well as warp factor. We impose bounds on stringy aspects of the model, such as the warp factor (f) and the induced gravity parameter ( m-tilde ). We study the parameter space of the model and find that the tensor-to-scalar ratio can be as low as r ≅ 6 × 10{sup −4}more » and inflation happens to be at GUT scale. In addition, we obtain the tilt of the tensor power spectrum and test the standard inflationary consistency relation (r = −8n{sub t}) against the latest bounds from the combined results of BKP+Laser Interferometer Gravitational-Waves Observatory (LIGO), and find that DBIG inflation predicts a red spectral index for the tensor power spectrum.« less
  • We generalize the embedding of induced-gravity inflation beyond the no-scale Supergravity presented in ref. [1] employing two gauge singlet chiral superfields, a superpotential uniquely determined by applying a continuous R and a discrete Z{sub n} symmetries, and a logarithmic Kähler potential including all the allowed terms up to fourth order in powers of the various fields. We show that, increasing slightly the prefactor (-3) encountered in the adopted Kähler potential, an efficient enhancement of the resulting tensor-to-scalar ratio can be achieved rendering the predictions of the model consistent with the recent BICEP2 results, even with subplanckian excursions of the originalmore » inflaton field. The remaining inflationary observables can become compatible with the data by mildly tuning the coefficient involved in the fourth order term of the Kähler potential which mixes the inflaton with the accompanying non-inflaton field. The inflaton mass is predicted to be close to 10{sup 14} GeV.« less
  • We generalize the embedding of induced-gravity inflation beyond the no-scale Supergravity presented in ref. http://dx.doi.org/10.1088/1475-7516/2014/08/057 employing two gauge singlet chiral superfields, a superpotential uniquely determined by applying a continuous R and a discrete ℤ{sub n} symmetries, and a logarithmic Kähler potential including all the allowed terms up to fourth order in powers of the various fields. We show that, increasing slightly the prefactor (−3) encountered in the adopted Kähler potential, an efficient enhancement of the resulting tensor-to-scalar ratio can be achieved rendering the predictions of the model consistent with the recent BICEP2 results, even with subplanckian excursions of the originalmore » inflaton field. The remaining inflationary observables can become compatible with the data by mildly tuning the coefficient involved in the fourth order term of the Kähler potential which mixes the inflaton with the accompanying non-inflaton field. The inflaton mass is predicted to be close to 10{sup 14} GeV.« less
  • I describe the first model of chaotic inflation in supergravity, which was proposed by Goncharov and the present author in 1983. The inflaton potential of this model has a plateau-type behavior V{sub 0}(1−(8/3) e{sup −√6|ϕ|}) at large values of the inflaton field. This model predicts n{sub s}=1−(2/N)≈0.967 and r=(4/(3N{sup 2}))≈4×10{sup −4}, in good agreement with the Planck data. I propose a slight generalization of this model, which allows to describe not only inflation but also dark energy and supersymmetry breaking.