Note on a Paper by Ooguri and Vafa

Understand

In a recent paper, Ooguri and Vafa [arXiv:1610.04564] argued that a mild extension of the Weak Gravity conjecture\cite{weakgrav} led to the conclusion that the only models of quantum gravity in AdS space with "radius large compared to the string scale" were models with exact AdS-SUSY.

• This note clarifies certain obscure parts of their argument by reinterpreting it as a statement about brane configurations in flat space.
• In that context the statement is that stable non-supersymmetric configurations of branes are characterized by charges in the torsion subgroup of K-theory and their only long range fields are gravitational and scalar.
• The field equations do not have large radius near horizon AdS solutions.