Observations on fluxes near anti-branes

TL;DR

This paper investigates the conditions under which anti-branes can be embedded into flux backgrounds without singularities, proposing that polarization into NS5 branes might resolve some issues and challenging recent no-go theorems.

Contribution

It demonstrates that unphysical singularities may be avoided through brane polarization and discusses conditions under which these solutions could be consistent, challenging previous assumptions.

Findings

Singularities in fluxes can potentially be avoided via NS5 brane polarization.

The polarization radius may significantly differ from probe approximations.

Certain assumptions in recent no-go theorems can be invalidated at zero temperature.

Abstract

We revisit necessary conditions for gluing local (anti-)D3 throats into flux throats with opposite charge. These consistency conditions typically reveal singularities in the three-form fluxes whose meaning is being debated. In this note we prove, under well-motivated assumptions, that unphysical singularities can potentially be avoided when the anti-branes polarise into spherical NS5 branes with a specific radius. If a consistent solution can then indeed be found, our analysis seems to suggests a rather large correction to the radius of the polarization sphere compared to the probe result. We furthermore comment on the gluing conditions at finite temperature and point out that one specific assumption of a recent no-go theorem can be broken if anti-branes are indeed to polarise into spherical NS5 branes at zero temperature.