Dynamical breaking of shift-symmetry in supergravity-based inflation
Abstract
Shift-symmetry is essential to protect the flatness of the potential, even beyond the super-Planckian vacuum expectation value (VEV) for an inflaton field. The breaking of the shift-symmetry can yield potentials suitable for super-Planckian excursion of the inflaton. The aim of this paper is to illustrate that it is indeed possible to break the shift-symmetry dynamically within 4 dimensional supergravity prior to a long phase of inflation. Thanks to the shift-symmetry, the leading contribu- tion to the inflaton potential is free from the dangerous exponential factor even after its breaking, which is the main obstacle to realizing the super-Planckian inflation in supergravity. But, in our simple model, the resulting inflaton potential is a cosine type potential rather than the power-law one and it is difficult to realize a super-Planckian breaking scale unfortunately.
Keywords
Cite
@article{arxiv.1405.3959,
title = {Dynamical breaking of shift-symmetry in supergravity-based inflation},
author = {Anupam Mazumdar and Toshifumi Noumi and Masahide Yamaguchi},
journal= {arXiv preprint arXiv:1405.3959},
year = {2014}
}
Comments
8 pages, no figure; v2: minor revision, estimation of the inflaton potential is corrected; v3: minor revision, published version, title is changed