A NUT Charge Weak Gravity Conjecture from Dimensional Reduction

TL;DR

This paper derives new constraints on higher-derivative corrections in 5d Einstein-Maxwell theory using the Weak Gravity Conjecture, revealing stronger bounds from 4d compactifications and extending the conjecture to topological charges like NUT charge.

Contribution

It introduces a novel application of the WGC to NUT-like topological charges, providing stronger bounds on gravitational theories through dimensional reduction analysis.

Findings

4d WGC bounds are stronger than 5d bounds.

Topological charges like NUT charge are constrained by WGC.

New constraints on purely gravitational theories derived.

Abstract

We analyze the constraints on four-derivative corrections to 5d Einstein-Maxwell theory from the black hole Weak Gravity Conjecture (WGC). We calculate the leading corrections to the extremal mass of asymptotically flat 5d charged solutions as well as 4d Kaluza-Klein compactifications. The WGC bounds from the latter, interpreted as 4d dyonic black holes, are found to be strictly stronger. As magnetic graviphoton charge lifts to a NUT-like charge in 5d, we argue that the logic of the WGC should apply to these topological charges as well and leads to new constraints on purely gravitational theories.