Pure Supersymmetric AdS and the Swampland

TL;DR

The paper shows that pure supergravity theories in AdS with high supersymmetry cannot be consistently embedded in quantum gravity, placing them in the Swampland and challenging the idea of scale separation.

Contribution

It demonstrates that pure AdS supergravity theories with sufficient supersymmetry lead to global symmetries in the flat space limit, thus are in the Swampland and incompatible with several Swampland conjectures.

Findings

Pure AdS supergravity theories with enough supersymmetry are in the Swampland.

Extreme scale separation in such theories is not possible.

These theories conflict with the Weak Gravity Conjecture and Distance Conjecture.

Abstract

We point out that pure supergravity theories in $AdS$ with enough supersymmetry lead, upon taking the large radius limit, to flat space quantum gravities with a nonperturbatively exact global symmetry, and are therefore in the Swampland. The argument applies to any $AdS$ supergravity with gauged R-symmetry group, including truncations of most well known examples, such as $AdS_5$ without the $S^5$ or $AdS_4$ without the $S^7$. This demonstrates that extreme scale separation, at least with enough supersymmetry, is not realizable. Moreover pure $AdS$ theories are also in conflict with some other Swampland principles including the Weak Gravity Conjecture and the (generalized) Distance Conjecture.