Breaking the scale invariance of the primordial power spectrum in Horava-Lifshitz Cosmology

TL;DR

This paper investigates how the spectral tilt of primordial perturbations varies in Horava-Lifshitz cosmology using the uniform approximation, revealing dependencies on inflation models and dispersion relation parameters.

Contribution

It introduces the use of the uniform approximation to compute the spectral index in Horava-Lifshitz cosmology both analytically and numerically.

Findings

Spectral index depends on inflation model parameters.

Analytical and numerical methods agree on spectral tilt calculations.

Clarifies the influence of modified dispersion relations on primordial spectra.

Abstract

We study the spectral tilt of primordial perturbations in Horava-Lifshitz cosmology. The uniform approximation, which is a generalization of the familiar Wentzel-Kramers-Brillouin (WKB) method, is employed to compute the spectral index both numerically and analytically in a closed form. We clarify how the spectral index depends on the inflation model and parameters in the modified dispersion relation.