Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

New leading contributions to non-gaussianity in single field inflation

Ignatios Antoniadis, Auttakit Chatrabhuti, Jules Cunat, Hiroshi Isono

Abstract

We compute the bispectrum of primordial density perturbations in CMB to second order in the slow-roll parameters of single field inflation. We correct previous results and found that next-to-leading order corrections can be of the same order as the leading order result in a large class of models, including hilltop inflation.

New leading contributions to non-gaussianity in single field inflation

Abstract

We compute the bispectrum of primordial density perturbations in CMB to second order in the slow-roll parameters of single field inflation. We correct previous results and found that next-to-leading order corrections can be of the same order as the leading order result in a large class of models, including hilltop inflation.

Paper Structure

This paper contains 23 sections, 252 equations, 4 figures.

Table of Contents

  1. Introduction
  2. Non-gaussianity of cosmological perturbations
  3. Scalar fluctuation and its action
  4. Equal-time three-point correlator
  5. Computing the three-point function
  6. The NLO vertices
  7. The lowest order vertices
  8. EoM vertex $\mathscr{O}_9$
  9. Total result
  10. Amplitude of the non-gaussianity
  11. Numerical estimate
  12. Conclusion
  13. Action
  14. Comment on the comoving gauge.
  15. The Schwinger-Keldysh path integral
  16. ...and 8 more sections

Figures (4)

  • Figure 1: Values of the functions $\tilde{K}_i(k_1,k_2,k_3)$ plotted for the rescaled momenta $x_1=1,\ x_2=k_2/k_1$ and $x_3=k_3/k_1$. The momenta are chosen to be ordered as $x_3\leq x_2\leq x_1$ and obey the triangle inequality $x_2+x_3\geq 1$.
  • Figure 2: Contour plot of the third Hubble flow parameter $\varepsilon_3$ as a function of the two free parameters of the model \ref{['Kahler']}-\ref{['ScalarPotential']}$A$ and $r$ (tensor-to-scalar ratio). The blue region corresponds to $|\varepsilon_3|\ge 10\,\varepsilon_2$ and the dashed curves to fixed values of $\varepsilon_3$ shown in the figure.
  • Figure 3: Values of the functions $f_i(k_1,k_2,k_3)$ and $\widehat{f}_i(k_1,k_2,k_3)$ plotted for the rescaled momenta $x_1=1,\ x_2=k_2/k_1$ and $x_3=k_3/k_1$. The momenta are chosen to be ordered as $x_3\leq x_2\leq x_1$ and obey the triangle inequality $x_2+x_3\geq 1$.
  • Figure :