Prospects of inflation with perturbed throat geometry

TL;DR

This paper investigates brane inflation within a warped deformed conifold, considering corrections from bulk coupling, and finds conditions under which the model produces sufficient inflation and aligns with observational data.

Contribution

It introduces a detailed analysis of perturbations in throat geometry affecting brane inflation, including numerical parameter constraints for observational consistency.

Findings

Effective potential can produce enough e-foldings.

Spectral index n_S aligns with observations.

Tensor-to-scalar ratio remains very low.

Abstract

We study brane inflation in a warped deformed conifold background that includes general possible corrections to the throat geometry sourced by coupling to the bulk of a compact Calabi-Yau space. We focus specifically, on the perturbation by chiral operator of dimension 3/2 in the CFT. We find that the effective potential in this case can give rise to required number of e-foldings and the spectral index $n_S$ consistent with observation. The tensor to scalar ratio of perturbations is generally very low in this scenario. The COBE normalization, however, poses certain difficulties which can be circumvented provided model parameters are properly fine tuned. We find the numerical values of parameters which can give rise to enough inflation, observationally consistent values of density perturbations, scalar to tensor ratio of perturbations and the spectral index $n_S$.