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arXiv · 1206.0728

Non-Gaussian signatures of Tachyacoustic Cosmology

Dennis Bessada
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Abstract

I investigate non-Gaussian signatures in the context of tachyacoustic cosmology, that is, a noninflationary model with superluminal speed of sound. I calculate the full non-Gaussian amplitude $\mathcal{A}$, its size $f_{\rm NL}$, and corresponding shapes for a red-tilted spectrum of primordial scalar perturbations. Specifically, for cuscuton-like models I show that $f_{\rm NL}\sim {\cal O}(1)$, and the shape of its non-Gaussian amplitude peaks for both equilateral and local configurations, the latter being dominant. These results, albeit similar, are quantitatively distinct from the corresponding ones obtained by Magueijo {\it{et. al}} in the context of superluminal bimetric models.

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Dennis Bessada. 2012-09-22. Non-Gaussian signatures of Tachyacoustic Cosmology. https://doi.org/10.1088/1475-7516%2F2012%2F09%2F018

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