Mimetic curvaton

In this paper, we investigate the primordial perturbations of the inflation model induced from the multifield mimetic gravity, where there are two fields during inflation, and both adiabatic and isocurvature perturbation modes are generated. We show that although the original adiabatic perturbation mode indeed loses the kinetic term due to the constraint equation, by applying the curvaton mechanism where one of the fields is viewed as a curvaton field, the adiabatic perturbation can be transferred from the isocurvature one at the end of inflation. Detailed calculations are performed for both inflationary and the consequent radiation-dominant and matter-dominant epochs. Therefore, the so-called nonpropagating problem of the adiabatic mode will not harm the multifield mimetic inflation models.

Automated summary

In this paper, the primordial perturbations of the inflation model induced from the multifield mimetic gravity are investigated. Both adiabatic and isocurvature perturbation modes are generated in the presence of two fields during inflation. It is shown that the adiabatic perturbation mode can be transferred from the isocurvature one by applying the curvaton mechanism, thus solving the nonpropagating problem. Detailed calculations are performed for different epochs, indicating that the multifield mimetic inflation models are not affected by this nonpropagating problem.