skip to main content

SciTech ConnectSciTech Connect

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

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:
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)
Sponsoring Org:
SCOAP3, CERN, Geneva (Switzerland)
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