The Weak Gravity Conjecture: A Review

Abstract

The Weak Gravity Conjecture holds that in a theory of quantum gravity, any gauge force must mediate interactions stronger than gravity for some particles. This statement has surprisingly deep and extensive connections to many different areas of physics and mathematics. Several variations on the basic conjecture have been proposed, including statements that are much stronger but are nonetheless satisfied by all known consistent quantum gravity theories. We review these related conjectures and the evidence for their validity in the string theory landscape. We also review a variety of arguments for these conjectures, which tend to fall into two categories: qualitative arguments which claim the conjecture is plausible based on general principles, and quantitative arguments for various special cases or analogues of the conjecture. We also outline the implications of these conjectures for particle physics, cosmology, general relativity, and mathematics. Finally, we highlight important directions for future research.

122 pages, 20 figures, invited review, to be published in Reviews of Modern Physics. v2: many improvements and added references

References in corpus (41)

• Building an AdS/CFT superconductor
• Generalized Global Symmetries
• On the Geometry of the String Landscape and the Swampland
• Causality, Analyticity and an IR Obstruction to UV Completion
• BICEP / Keck XIII: Improved Constraints on Primordial Gravitational Waves using Planck, WMAP, and BICEP/Keck Observations through the 2018 Observing Season
• Monodromy in the CMB: Gravity Waves and String Inflation
• Symmetries and Strings in Field Theory and Gravity
• The Swampland: Introduction and Review
• Dark Matter and Dark Radiation
• A Natural Framework for Chaotic Inflation
• Black Hole Bound on the Number of Species and Quantum Gravity at LHC
• Super-Planckian Spatial Field Variations and Quantum Gravity
• The Powers of Monodromy
• Natural inflation with multiple sub-Planckian axions
• Unbroken B-L Symmetry
• The Weak Gravity Conjecture in three dimensions
• Natural Inflation and Quantum Gravity
• Universal Bound on Dynamical Relaxation Times and Black-Hole Quasinormal Ringing
• Infrared Consistency and the Weak Gravity Conjecture
• On the Possibility of Large Axion Moduli Spaces
• Branching of quasinormal modes for nearly extremal Kerr black holes
• First Order Description of Black Holes in Moduli Space
• The Weak Gravity Conjecture and Effective Field Theory
• Quantum Corrections in 4d N=1 Infinite Distance Limits and the Weak Gravity Conjecture
• Can Gravitational Instantons Really Constrain Axion Inflation?
• A note on Gauge Theories Coupled to Gravity
• Near-Extreme Black Holes and the Universal Relaxation Bound
• Quasinormal modes of charged fields around a Reissner-Nordström black hole
• Very Hairy Inflation
• Axion Mass from Magnetic Monopole Loops
• Physics of Infinite Complex Structure Limits in eight Dimensions
• Membrane Limits in Quantum Gravity
• A proof of the weak gravity conjecture
• A New Spin on the Weak Gravity Conjecture
• Weak gravity versus de Sitter
• Gravity Cutoff in Theories with Large Discrete Symmetries
• The unbearable lightness of charged gravitini
• Corrections to Extremal Black Holes from Iyer-Wald Formalism
• The Entropy Shift and Extremality Shift at Zero Temperature
• Gravitational Instabilities and Censorship of Large Scalar Field Excursions
• The Weak Gravity Conjecture and BPS Particles

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• Higher Derivative Supergravities in Diverse Dimensions
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• Coupling Constants as Conserved Charges in Black Hole Thermodynamics
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• WGC and WCC for charged black holes with quintessence and cloud of strings
• On the Origin of Species Thermodynamics and the Black Hole - Tower Correspondence
• WGC as WCCC protector: The Synergistic Effects of various Parameters in Identifying WGC candidate Models
• The Standard Model from String Theory: What Have We Learned?
• Approximate symmetries and quantum error correction
• Detectable and defect-free dark photon dark matter
• Self-Binding Energies in AdS
• Negative Corrections to Black Hole Entropy from String Theory
• Proving the Weak Gravity Conjecture in Perturbative String Theory, Part I: The Bosonic String
• Through the Looking Glass into the Dark Dimension: Searching for Bulk Black Hole Dark Matter with Microlensing of X-ray Pulsars
• Universality on thermodynamic relation with corrections in de Sitter black holes
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• EGUP corrected thermodynamics of RN-AdS black hole with quintessence matter
• Thermodynamic relation of accelerating black holes in anti-de Sitter spacetime
• Asymptotic safety, quantum gravity, and the swampland: a conceptual assessment
• First order corrections to black hole thermodynamics: a simple approach enhanced
• An Introduction to the Weak Gravity Conjecture
• Lectures in Quantum Gravity
• Static spheres and Aschenbach effect for black holes in massive gravity
• Axion species scale and axion weak gravity conjecture-like bound
• On the cosmological abundance of magnetic monopoles
• Newton vs. Coulomb in AdS/CFT and the Weak Gravity Conjecture
• Assessing WGC Compatibility in ModMax Black Holes via Photon Spheres Analysis and WCCC Validation
• Fluctuating Ensemble Averages and the BTZ Threshold
• Cosmic-Quantum Connections: Assessing the Viability of Weak Gravity and Weak Cosmic Censorship Conjectures in Kerr-Newman-Kiselev-Letelier Black Hole
• Hitchhiker's Guide to the Swampland: The Cosmologist's Handbook to the string-theoretical Swampland Programme
• Universal Relations with the Non-Extensive Entropy Perspective
• Higher spin swampland conjecture for massive AdS${}_3$ gravity
• Morse-Bott inequalities, Topology Change and Cobordisms to Nothing
• Refined BPS numbers on compact Calabi-Yau threefolds from Wilson loops
• Stability of Extremal Black Holes and Weak Cosmic Censorship Conjecture in Kiselev Spacetime
• De Sitter space constraints on brane tensions and couplings
• Immortality through the dark forces: Dark-charge primordial black holes as dark matter candidates
• ISCOs and the weak gravity conjecture bound in higher derivative theories of gravity
• Bounds on complex structure moduli values for perturbative control
• Quantum gravitational corrections to Reissner-Nordström black hole thermodynamics and their implications for the weak gravity conjecture
• Breaking Free from the Swampland of Impossible Universes through the DESI Portal
• Universality on thermodynamic relation with corrections in Einstein-Bel-Robinson gravity Black hole
• Extremalization approach to black hole thermodynamics: perturbations around higher-derivative gravities
• Center Symmetry Breaking in Calabi--Yau Compactifications