Primordial perturbations and inflation in holographic cosmology
| Autor: | Davi C. Rodrigues, Neven Bilić, Nicolas R. Bertini |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Inflation (cosmology)
Physics 010308 nuclear & particles physics Scalar (mathematics) FOS: Physical sciences Spectral density General Relativity and Quantum Cosmology (gr-qc) Astrophysics::Cosmology and Extragalactic Astrophysics Inflaton Type (model theory) 01 natural sciences General Relativity and Quantum Cosmology symbols.namesake 0103 physical sciences symbols Tensor Brane Einstein 010306 general physics Mathematical physics |
| Zdroj: | Physical Review D. 102 |
| ISSN: | 2470-0029 2470-0010 |
| 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: | OpenAIRE |
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