## Abstract

We study observational signatures of two classes of anisotropic inflationary models in which an inflaton field couples to (i) a vector kinetic term F_{μ}νF_{μ}ν and (ii) a two-form kinetic term H_{μ}νλHμνλ. We compute the corrections from the anisotropic sources to the power spectrum of gravitational waves as well as the two-point cross correlation between scalar and tensor perturbations. The signs of the anisotropic parameter g_{*} are different depending on the vector and the two-form models, but the statistical anisotropies generally lead to a suppressed tensor-to-scalar ratio r and a smaller scalar spectral index n_{s} in both models. In the light of the recent Planck bounds of n_{s} and r, we place observational constraints on several different inflaton potentials such as those in chaotic and natural inflation in the presence of anisotropic interactions. In the two-form model we also find that there is no cross correlation between scalar and tensor perturbations, while in the vector model the cross correlation does not vanish. The non-linear estimator f_{NL} of scalar non-Gaussianities in the two-form model is generally smaller than that in the vector model for the same orders of g _{*}|, so that the former is easier to be compatible with observational bounds of non-Gaussianities than the latter.

Original language | English |
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Article number | 009 |

Journal | Journal of Cosmology and Astroparticle Physics |

Volume | 2013 |

Issue number | 12 |

DOIs | |

Publication status | Published - 2013 Dec |

Externally published | Yes |

## Keywords

- cosmological parameters from CMBR
- cosmological perturbation theory
- ination
- non-gaussianity

## ASJC Scopus subject areas

- Astronomy and Astrophysics