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arXiv · 2007.02332

Primordial perturbations and inflation in holographic cosmology

Nicolas R. Bertini·Neven Bilic·Davi C. Rodrigues
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Abstract

We consider an inflationary scenario in the holographic braneworld with a cosmological fluid occupying the 3+1 dimensional brane located at the holographic boundary of an asymptotic ADS$_5$ bulk. The contribution of the boundary conformal field can be represented as a modification of Einstein's equations on the boundary. Using these effective Einstein equations we calculate the cosmological perturbations and derive the corresponding power spectra assuming a general $k$-essence type of inflaton. We find that the braneworld scenario affects the scalar power spectrum only in the speed of sound dependence on the slow-roll parameters whereas there is no change in the tensor power spectrum. This implies that the changes in the spectral indices appear at the second order in the slow-roll parameter expansion.

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Nicolas R. Bertini, Neven Bilic, Davi C. Rodrigues. 2020-07-05. Primordial perturbations and inflation in holographic cosmology. https://doi.org/10.1103/physrevd.102.123505

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