Aspects of brane-antibrane inflation

TL;DR

This paper presents a dynamical mechanism for brane-antibrane inflation that naturally solves fine-tuning issues by trapping branes in metastable minima, leading to a viable inflationary scenario testable by future CMB experiments.

Contribution

It introduces a new dynamical trapping mechanism for branes in inflation models, reducing fine-tuning and linking spectral index running with potential tilt for observational tests.

Findings

Branes can be trapped at metastable minima, enabling sufficient inflation.

The model predicts a correlation between spectral index running and tilt.

Potential for future CMB experiments to test the model.

Abstract

I describe a dynamical mechanism for solving the fine-tuning problem of brane-antibrane inflation. By inflating with stacks of branes and antibranes, the branes can naturally be trapped at a metastable minimum of the potential. As branes tunnel out of this minimum, the shape of the potential changes to make the minimum shallower. Eventually the minimum disappears and the remaining branes roll slowly because the potential is nearly flat. I show that even with a small number of branes, there is a good chance of getting enough inflation. Running of the spectral index is correlated with the tilt in such a way as to provide a test of the model by future CMB experiments.