Loop corrections to the antibrane potential

TL;DR

The paper addresses whether anti-D3 brane uplifting in Klebanov-Strassler throats is viable in the weak backreaction regime. It uses a brane effective action approach to derive the worldvolume theory and shows that the inter-brane potential along the bottom $S^3$ is flat to all loops. This flatness agrees with strong-coupling polarization results and suggests a non-gapped spectrum with potential tachyonic directions off the $S^3$, challenging uplift mechanisms based on anti-D3 branes. Overall, the study connects open-string loop computations and brane-world analyses to argue against reliable de Sitter uplifting from anti-D3 branes in these settings.

Abstract

Antibranes provide some of the most generic ways to uplift Anti-de Sitter flux compactifications to de Sitter, and there is a growing body of evidence that antibranes placed in long warped throats such as the Klebanov-Strassler warped deformed conifold solution have a brane-brane-repelling tachyon. This tachyon was first found in the regime of parameters in which the backreaction of the antibranes is large, and its existence was inferred from a highly nontrivial cancellation of certain terms in the inter-brane potential. We use a brane effective action approach, similar to that proposed by Michel, Mintun, Polchinski, Puhm and Saad in arXiv:1412.5702, to analyze antibranes in Klebanov-Strassler when their backreaction is small, and find a regime of parameters where all perturbative contributions to the action can be computed explicitly. We find that the cancellation found at strong coupling is also present in the weak-coupling regime, and we establish its existence to all loops. Our calculation indicates that the spectrum of the antibrane worldvolume theory is not gapped, and may generically have a tachyon. Hence uplifting mechanisms involving antibranes remain questionable even when backreaction is small.

Figures (5)

• Figure 1: Field-theory loop corrections to the scalar mass, involving the trilinear and quadrilinear scalar couplings and the Yukawa couplings.
• Figure 2: Open-string loop expansion. Crosses represents open string vertex operators; red is used for planar diagrams, and blue for non-planar diagrams.
• Figure 3: An illustration of the different regimes of parameters. Some recent investigations carried out in the different limits include: A. Michel:2014lva, B. Cohen-Maldonado:2015ssa, C. Bena:2014jaa, D. The present work. The AdS/CFT-like decoupling limit is shaded in blue, and the vertical (green) dashed line is $g_s \overline{N}_{\!3} = 1$.
• Figure 4: Contributions to the antibrane potential within an EFT of the brane and supergravity fields Michel:2014lva. Crosses represent external supergravity fields.
• Figure 5: Closed-string loop diagrams of which the diagrams in Fig. \ref{['fig:bulkdiagram']} are limits. Crosses represent closed string vertex operators corresponding to the external legs in Fig. \ref{['fig:bulkdiagram']}.