Loop corrections to the antibrane potential

TL;DR

This paper investigates the stability of antibranes in warped flux compactifications, finding that a tachyonic instability persists even with small backreaction, challenging their use for uplifting to de Sitter space.

Contribution

The authors perform a loop-level analysis of antibranes in the Klebanov-Strassler background, demonstrating the persistence of tachyonic instabilities across coupling regimes.

Findings

Cancellation of terms in the potential persists at all loops.

Spectrum of the worldvolume theory may contain a tachyon.

Uplifting mechanisms with antibranes are potentially unstable.

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.