Polchinski-Strassler does not uplift Klebanov-Strassler
Iosif Bena, Mariana Grana, Stanislav Kuperstein, Stefano Massai
TL;DR
This work analyzes the backreaction of smeared anti-D3 branes in the KS background and shows that IR three-form flux singularities cannot be resolved by Polchinski-Strassler-type polarization into D5 branes wrapping the conifold's $S^2$. By employing the Papadopoulos-Tseytlin ansatz and a two-fold first-order formalism with conjugate momenta $oldsymbol{\xi}$, it proves that no IR-regular solution exists that connects to KS in the UV; a global argument and a detailed irreguar analysis confirm the same obstruction. The D5 polarization potential for a probe D5 with dissolved anti-D3 charge has no metastable minimum for any IR data, indicating that brane polarization does not cure the singularity and that anti-D3 uplifting of AdS to dS is unlikely in this setup. The results strengthen the view that anti-branes in flux backgrounds do not yield metastable vacua and call for alternative uplift mechanisms. Overall, the paper provides a robust no-go for polarization-based resolution and emphasizes the need to reassess claims of a large dS landscape in string theory.
Abstract
Anti-D3-branes at the tip of the Klebanov-Strassler solution with D3-charge dissolved in fluxes give rise, in the probe approximation, to a metastable state. The fully back-reacted smeared solution has singular three-form fluxes in the IR, whose presence suggests a stringy resolution by brane polarization a la Polchinski-Strassler. In this paper we show that there is no polarization into anti-D5-branes wrapping the $S^2$ of the conifold at a finite radius. The singularities therefore do not seem to be physical, signaling that antibranes cannot be used to uplift AdS and obtain a very large landscape of de Sitter vacua in string theory.
