Scale dependence of $f_{NL}$ in N-flation
Cosmology and Nongalactic Astrophysics
2011-01-27 v3 General Relativity and Quantum Cosmology
High Energy Physics - Phenomenology
High Energy Physics - Theory
Abstract
Adopting the horizon-crossing approximation, we derive the spectral index of in general N-flation model. Axion N-flation model is taken as a typical model for generating a large which characterizes the size of local form bispectrum. We find that its tilt is negligibly small when all inflatons have the same potential, but a negative detectable can be achieved in the axion N-flation with different decay constants for different inflatons. The measurement of can be used to support or falsify the axion N-flation in the near future.
Cite
@article{arxiv.1009.3326,
title = {Scale dependence of $f_{NL}$ in N-flation},
author = {Qing-Guo Huang},
journal= {arXiv preprint arXiv:1009.3326},
year = {2011}
}
Comments
15 pages, 2 figures; a subsection with detectable scale dependence of f_NL added; more discussions added and version accepted for publication in JCAP