Uplifting Runaways

TL;DR

This paper shows that uplifting stabilized KS flux compactifications with anti-D3 branes generically leads to a conifold runaway driven by a very light conifold modulus $S$, undermining KKLT-like de Sitter constructions under tadpole and hierarchy constraints. The authors compute the warp-corrected stabilization potential for $S$, the anti-D3 uplift energy, and the total potential, finding that a hierarchical de Sitter vacuum requires flux choices that violate tadpole bounds, or destroy perturbative control. They connect these results to the de Sitter swampland conjecture by deriving bounds on $V'/V$ and show consistency with the conjecture even when $V$ is parametric small. The work also discusses implications for holographic QCD, notably the possible existence of a Klebanov-Strassler black hole, and outlines three avenues to avoid the runaway, highlighting the tension between controlled uplifting and swampland criteria.

Abstract

We find a mechanism by which antibranes placed in a warped deformed conifold throat can destroy the stabilization of the size of the sphere at the tip, collapsing it to zero size. This conifold destabilization mechanism can be avoided by turning on a large amount of flux on the sphere, but tadpole cancelation makes this incompatible with a hierarchy of scales in a Type IIB flux compactification. This indicates that antibrane uplift cannot be used to construct stable de Sitter vacua with a small cosmological constant in perturbative String Theory. The values of V and V' for these KKLT-like scenarios can be parametrically small, but we find that V'/V is still consistent with the de Sitter swampland conjecture. Our results also suggest that there should exist a Klebanov-Strassler black hole, holographically dual to a deconfined phase with spontaneously broken chiral symmetry.

Figures (3)

• Figure 1: The potential $V_{KS}$ of Douglas:2007tu for the complex structure modulus $S$ of the Klebanov-Strassler throat given in \ref{['eq:VKS']}. The solid blue line corresponds to the full potential, while the dotted orange line does shows the naïve potential that does not take into account the effects of warping ($c' = 0$). Both potentials have the same supersymmetric minimum but differ drastically at small $S$.
• Figure 2: The contribution $V_{\overline{D3}}$ (solid blue line) of an $\overline{D3}$-brane placed in the Klebanov-Strassler throat to the potential for $S$. The two other lines represent the original potential $V_{KS}$ (dotted orange line) for the specific value $\sqrt{g_s} M = 6$ as well as the superposition $V_{KS} + V_{\overline{D3}}$ (dashed green line).
• Figure 3: The combined potential $V_{KS} + V_{\overline{D3}}$ for one anti-D3 brane and $\sqrt{g_s}M = 5$, 7 and 12. All three graphs are drawn for the same ratio $K/M = 5$. A local minimum only exists if $M$ is larger than the threshold value $M_\text{min} \approx 6.8$.