Persistence of Demirtas–Kim–McAllister–Moritz AdS vacua after integrating in light domain-wall modes

Determine whether the supersymmetric anti–de Sitter vacua with exponentially small cosmological constant constructed by Demirtas, Kim, McAllister, Moritz, and collaborators persist once the axion-like scalar associated with NS5′ polarization (and the corresponding domain wall degrees of freedom) is integrated into the four-dimensional effective field theory.

Background

The authors show that in racetrack-based KKLT-like models without warping, the domain wall bound is parametrically violated because the AdS cosmological constant is exponentially small while the Kaluza–Klein scale decreases only polynomially. They interpret this as indicating that domain wall bubbles are light and must be included in the EFT.

By invoking the KPV mechanism, the domain wall degrees of freedom correspond to an axion-like field ψ whose potential barriers are set by the NS5-brane tension. Integrating in ψ transforms thin (fundamental) walls into thick walls within the EFT, potentially altering (or invalidating) the AdS vacua; the authors state they do not know whether these vacua survive after including these light modes.