title: Naturalness and the weak gravity conjecture.
abstract: The weak gravity conjecture (WGC) is an ultraviolet consistency condition asserting that an Abelian force requires a state of charge q and mass m with q>m/m_{Pl}. We generalize the WGC to product gauge groups and study its tension with the naturalness principle for a charged scalar coupled to gravity. Reconciling naturalness with the WGC either requires a Higgs phase or a low cutoff at Λ∼qm_{Pl}. If neither applies, one can construct simple models that forbid a natural electroweak scale and whose observation would rule out the naturalness principle.
authors.affiliation: Walter Burke Institute for Theoretical Physics, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: Clifford
authors.initials: C
authors.lastname: Cheung
authors.affiliation: Walter Burke Institute for Theoretical Physics, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: Grant N
authors.initials: GN
authors.lastname: Remmen