Holographic Systematics of D-brane Inflation

TL;DR

This paper systematically analyzes corrections to the inflaton potential in D-brane inflation within warped deformed conifold geometries, identifying dominant contributions from specific operators and their implications for inflationary models.

Contribution

It provides a comprehensive framework for understanding potential corrections in D-brane inflation, highlighting the roles of relevant operators and symmetry considerations.

Findings

Non-chiral operator of dimension 2 affects inflaton mass.

Discrete symmetries can allow fine-tuning of the inflaton potential.

Inflationary models resemble inflection point scenarios from D7-brane embeddings.

Abstract

We provide a systematic treatment of possible corrections to the inflaton potential for D-brane inflation in the warped deformed conifold. We consider the D3-brane potential in the presence of the most general possible corrections to the throat geometry sourced by coupling to the bulk of a compact Calabi-Yau space. This corresponds to the potential on the Coulomb branch of the dual gauge theory, in the presence of arbitrary perturbations of the Lagrangian. The leading contributions arise from perturbations by the most relevant operators that do not destroy the throat geometry. We find a generic contribution from a non-chiral operator of dimension $\Delta=2$ associated with a global symmetry current, resulting in a negative contribution to the inflaton mass-squared. If the Calabi-Yau preserves certain discrete symmetries, this is the dominant correction to the inflaton potential, and fine-tuning of the inflaton mass is possible. In the absence of such discrete symmetries, the dominant contribution comes from a chiral operator with $\Delta=3/2$, corresponding to a $\phi^{3/2}$ term in the inflaton potential. The resulting inflationary models are phenomenologically similar to the inflection point scenarios arising from specific D7-brane embeddings, but occur under far more general circumstances. Our strategy extends immediately to other warped geometries, given sufficient knowledge of the Kaluza-Klein spectrum.