Evolution of Perturbations in a Noncommutative Braneworld Inflation

TL;DR

This paper investigates how noncommutative geometry influences the evolution of cosmological perturbations in a braneworld inflation model, revealing differences in perturbation decay and inflation duration compared to the commutative case.

Contribution

It introduces a coherent state approach to noncommutativity in braneworld inflation and analyzes its effects on perturbation dynamics and inflation duration.

Findings

Early universe exhibits phantom evolution with imaginary sound speed.

Perturbation amplitude decays faster in the commutative regime.

Noncommutative regime requires fewer e-folds for successful inflation.

Abstract

Following our previous work in noncommutative braneworld inflation (arXiv:0911.4418), in this paper we use the smeared, coherent state picture of noncommutativity to study evolution of perturbations in a noncommutative braneworld scenario. We show that in this setup, the early stage of the universe evolution has a phantom evolution with imaginary effective sound speed. We show also that the amplitude of perturbations in the commutative regime decays faster than the noncommutative regime with the same parameter values, and as a result we need smaller number of e-folds in the noncommutative regime to have a successful braneworld inflation.