Tension of non-BPS exotic branes

Determine the tensions of conjectured non-BPS codimension-two exotic branes in string theory as functions of the moduli, and identify regions of moduli space where these tensions are sufficiently small in Planck units so that macroscopic loops of the corresponding branes are not hidden behind their Schwarzschild horizons.

Background

The paper argues that macroscopic loops of codimension-two branes can be studied by asymptotic observers only when their tensions are small enough in Planck units to avoid being hidden behind event horizons. For BPS exotic branes, dualities ensure such regimes exist somewhere in moduli space. For non-BPS exotic branes, however, their tensions are not known a priori, obstructing analogous tests of their existence and associated monodromies.

Clarifying the moduli dependence of the tensions of non-BPS exotic branes (e.g., reflection 7-branes) would determine whether large, accessible loops can exist and would enable direct tests of their predicted monodromies and the associated discrete gauge symmetries.