Compactness of gauge symmetries in quantum gravity
Establish that continuous gauge groups in consistent quantum gravity are compact, thereby ensuring that electric charge spectra form lattices.
References
The charges form a lattice if the gauge group is compact (e.g., U(1)N), where the compactness of the gauge group is yet another swampland conjecture [Banks:2010zn].
— Proving the Weak Gravity Conjecture in Perturbative String Theory, Part I: The Bosonic String
(2401.14449 - Heidenreich et al., 25 Jan 2024) in Section 1 (Introduction), footnote to the charge lattice discussion