Develop theoretical tools for the small g_s M regime in the KS throat

Develop theoretical methods that enable analysis of the Klebanov–Strassler throat in the regime of small g_s M, including formulating and performing controlled string perturbation theory (e.g., via open–closed superstring field theory or alternative approaches) beyond the large-radius approximation, so that the background and stability properties can be reliably studied when the product of the string coupling g_s and flux number M is not large.

Background

Throughout the paper the authors construct and analyze a perturbative background solution for the Klebanov–Strassler throat using open–closed superstring field theory in the large radius limit combined with a near-tip double scaling. This approach relies on g_s M being large to treat fluxes as small deformations over the deformed conifold and to control the worldsheet and field-theoretic expansions.

While these techniques yield results consistent with KPV in the controlled regime, extending them to the small g_s M regime remains challenging. New theoretical tools would be required to access and analyze backgrounds with strong warping and large Ramond flux without relying on large-radius approximations, and to paper supersymmetry breaking and stability in that parameter range.