Mimetic Curvaton

TL;DR

This paper explores how the curvaton mechanism in multi-field mimetic gravity models allows the transfer of isocurvature perturbations into adiabatic ones, resolving issues related to the non-propagating adiabatic mode.

Contribution

It demonstrates that in multi-field mimetic inflation, the curvaton mechanism enables the transfer of isocurvature to adiabatic perturbations, addressing the non-propagating problem.

Findings

Adiabatic perturbations can be generated from isocurvature modes via the curvaton mechanism.

The non-propagating problem of adiabatic modes does not affect multi-field mimetic inflation.

The transfer process is detailed for inflation and matter-dominant epochs.

Abstract

In this paper, we investigate the primordial perturbations of inflation model induced from the multi-field mimetic gravity, where there are two field during inflation, and thus both adiabatic and isocurvature perturbation modes are generated. We show that although it is true that the original adiabatic perturbation mode loses the kinetic term due to the constraint equation, by applying the curvaton mechanism where one of the field is viewed as curvaton field, the adiabatic perturbation can actually be transferred from the isocurvature one at the end of inflation. Detailed calculations are performed for both inflationary and the consequent matter-dominant epochs. Therefore, the so-called "non-propagating problem" of the adiabatic mode will actually do no harm to the multi-field mimetic inflation models.