English

Primordial perturbations and inflation in holographic cosmology

General Relativity and Quantum Cosmology 2022-07-05 v3

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 ADS5_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 kk-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.

Keywords

Cite

@article{arxiv.2007.02332,
  title  = {Primordial perturbations and inflation in holographic cosmology},
  author = {Nicolas R. Bertini and Neven Bilic and Davi C. Rodrigues},
  journal= {arXiv preprint arXiv:2007.02332},
  year   = {2022}
}

Comments

20 pages, 1 figure. The field equations are corrected by adding a new term which vanishes for a conformally flat background metric. The resulting change of perturbed field equations does not affect the results and conclusions. The corrections match the Erratum published in PRD