Non-canonical two-field inflation to order $\xi^2$

TL;DR

This paper develops analytical formulas for the primordial power spectra in non-canonical two-field inflation models, incorporating corrections up to order 6362; it improves understanding of super-horizon perturbations and matches numerical results.

Contribution

It provides the first analytical calculation of power spectra to order 6362 in non-canonical two-field inflation models, with an improved method for super-horizon perturbations.

Findings

Analytical power spectra match numerical simulations well.

Corrections of order 6362 are significant for accurate modeling.

Super-horizon perturbation analysis is improved with a new method.

Abstract

In non-canonical two-field inflation models, deviations from the canonical model can be captured by a parameter $\xi$. We show this parameter is usually one half of the slow-roll order and analytically calculate the primordial power spectra accurate to order $\xi^2$. The super-horizon perturbations are studied with an improved method, which gives a correction of order $\xi^2$. Three typical examples demonstrate that our analytical formulae of power spectra fit well with numerical simulation.