Density perturbations from curvatons revisited

18th International Symposium on Particles Strings and Cosmology

Kobayashi, Takeshi^1,2

Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, ON M5S 3H8, Canada^1

Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, ON N2L 2Y5, Canada^2

关键词: Density perturbation;    Key feature;    Non-uniform;    Nongaussianity;    Second orders;    Systematic framework;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/485/1/012018/pdf
DOI  :  10.1088/1742-6596/485/1/012018

来源: IOP

【 摘 要 】

We investigate density perturbations sourced by a curvaton with a generic energy potential. The key feature of a curvaton potential which deviates from a quadratic is that the curvaton experiences a non-uniform onset of its oscillation. This sources additional contributions to the resulting density perturbations, and we especially find that curvaton potentials that are flatter compared to a quadratic lead to enhancement of the linear and second-order density perturbations, while steepened potentials can generate strongly scale-dependent non-Gaussianity. As such examples, we study pseudo-Nambu- Goldstone curvatons and self-interacting curvatons. Our analyses are analytic, and thus provide a systematic framework for studying curvatons in general. The discussion in this paper are based on [1, 2].