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arXiv · 1103.1740

Primordial non-Gaussianity from G-inflation

Tsutomu Kobayashi·Masahide Yamaguchi·Jun'ichi Yokoyama
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Abstract

We present a comprehensive study of primordial fluctuations generated from G-inflation, in which the inflaton Lagrangian is of the form $K(ϕ, X)-G(ϕ, X)\Boxϕ$ with $X=-(\partialϕ)^2/2$. The Lagrangian still gives rise to second-order gravitational and scalar field equations, and thus offers a more generic class of single-field inflation than ever studied, with a richer phenomenology. We compute the power spectrum and the bispectrum, and clarify how the non-Gaussian amplitude depends upon parameters such as the sound speed. In so doing we try to keep as great generality as possible, allowing for non slow-roll and deviation from the exact scale-invariance.

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Tsutomu Kobayashi, Masahide Yamaguchi, Jun'ichi Yokoyama. 2011-05-13. Primordial non-Gaussianity from G-inflation. https://doi.org/10.1103/physrevd.83.103524

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