Primordial perturbations and inflation in holographic cosmology
| Autor: | Bertini, Nicolas R., Bilic, Neven, Rodrigues, Davi C. |
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| Rok vydání: | 2020 |
| Předmět: | |
| Zdroj: | Phys. Rev. D 102, 123505 (2020); Phys. Rev. D 105, 129901 (2022) (Erratum) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevD.102.123505 |
| Popis: | 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. Comment: 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 |
| Databáze: | arXiv |
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