Weak Gravity Conjecture

Every consistent theory of quantum gravity containing a gravitational sector and a U(1)U(1) gauge field contains a charged particle or state with charge qq and mass mm satisfying qm≥(QM)ext\frac{q}{m}\geq\left(\frac{Q}{M}\right)_{\mathrm{ext}}, where (QM)ext\left(\frac{Q}{M}\right)_{\mathrm{ext}} is the charge-to-mass ratio of an extremal black hole in the same theory, with charge normalized in the same conventions.

References

Additional references

Progress summary

Refreshed
Claimed progress

The conjecture remains unproved in general; a new calculation derives supporting bounds only for selected black-hole models.

The Weak Gravity Conjecture, proposed by Arkani-Hamed, Motl, Nicolis, and Vafa in 2006, asserts that quantum-gravity theories contain sufficiently charged objects, schematically requiring a charge-to-mass ratio at least that of an extremal black hole. Its precise formulation, especially in anti-de Sitter space, remains unsettled.

Known results

  • The original proposal did not prove extremal black-hole decay or the bound (Arkani-Hamed, Motl, Nicolis, and Vafa, 2006).
  • Higher-derivative and entropy arguments support the conjecture in broad classes but require additional assumptions (Cheung, Liu, and Remmen; Cheung et al., 2018).
  • Explicit compactification examples contradict lattice and other stronger versions, without refuting every mild version.
  • Numerical anti-de Sitter studies support a connection with cosmic censorship but provide no general proof (Crisford and Santos, 2017).

2026 near-horizon bounds

Saeed Noori Gashti, Behnam Pourhassan, and İzzet Sakallı derive model-dependent bounds relating the conjecture to near-horizon AdS2\mathrm{AdS}_2 data, including dRGT massive gravity and Einstein–ModMax black holes. The reported symbolic and numerical checks support the calculation within those assumptions, but do not establish the conjecture for arbitrary quantum-gravity theories; independent assessment was not found.

Current status (as of October 2026): Model-dependent near-horizon bounds have been claimed, but the general Weak Gravity Conjecture remains open and the new derivation is unverified.

Sources

Solutions 0

No solutions have been posted yet.