Holographic systematics of D-brane inflation

Abstract

We provide a systematic treatment of possible corrections to the inflaton potential for Dbrane 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 ∆ = 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 ∆ = 3/2, corresponding to a φ 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.

Towards a warped inflationary brane scanning

“…However in light of recent results in Ref. [15] indicating that V bulk (φ) can be generically comparable to V stab. (φ), it is clearly necessary to apply such general results and scan the enlarged parameter space to include the bulk corrections.…”

“…[14]. The gauge/string duality then allows us to parametrize these symmetry breaking bulk perturbations to the inflaton potential by coupling dual (approximately) conformal field theory to these bulk modes [15]. Combining these with the D3-D3 interaction, we can schematically parametrize the total potential of the inflaton φ including both local and bulk effects, experienced by a mobile D3 brane in the warped deformed conifold as…”

“…2 Although we follow similar scheme as in Ref. [15], we do not partition V stab. (φ) such that the inflaton mass term ∼ H 2 φ 2 is singled out.…”

Inflation and String Theory

“…We briefly summarize the results. We split the bulk contributions into homogeneous solutions of the six-dimensional Laplace equation [317] 58) and inhomogeneous contributions sourced by flux [640],…”

“…In the noncompact, supersymmetric Klebanov-Strassler background, e 4A = α, i.e. Φ − = 0, but in a finite warped throat, supersymmetry breaking and moduli stabilization in the bulk source perturbations of Φ − and of G − [42,317] -see (5.52). In turn, these perturbations source corrections to the metric.…”