Computation of inflationary cosmological perturbations in the power-law inflationary model using the phase-integral method

Clara Rojas, Víctor M. Villalba
2007 Physical Review D  
The phase-integral approximation devised by Fr\"oman and Fr\"oman, is used for computing cosmological perturbations in the power-law inflationary model. The phase-integral formulas for the scalar and tensor power spectra are explicitly obtained up to ninth-order of the phase-integral approximation. We show that, the phase-integral approximation exactly reproduces the shape of the power spectra for scalar and tensor perturbations as well as the spectral indices. We compare the accuracy of the
more » ... accuracy of the phase-integral approximation with the results for the power spectrum obtained with the slow-roll and uniform approximation methods.
doi:10.1103/physrevd.75.063518 fatcat:ewjosgguubd7pnj2qcvwzjud3m