Confined monopoles and failure of the Lattice Weak Gravity Conjecture

TL;DR

This paper investigates why certain theories of quantum gravity violate the Lattice Weak Gravity Conjecture, revealing a universal pattern involving fractionally charged monopoles confined by flux tubes and their relation to non-invertible symmetries.

Contribution

It identifies universal features and mechanisms behind LWGC violations, linking confined monopoles and non-invertible symmetries across various theoretical frameworks.

Findings

LWGC violation correlates with fractionally charged confined monopoles.

Confining flux tubes become light as LWGC violation intensifies.

Monopoles deconfine when LWGC-violating particles become infinitely massive.

Abstract

Almost all known theories of quantum gravity satisfy the Lattice Weak Gravity Conjecture (LWGC), which posits that a consistent theory of quantum gravity must have a superextremal particle at every site in the charge lattice. However, a number of theories have been observed to violate the LWGC; such theories exhibit only a (finite index) sublattice of superextremal particles. This paper aims to identify universal features and patterns associated with LWGC violation across numerous examples in effective field theory, string theory, and M-theory. Some of these examples have appeared previously in the literature, while others are novel. In all such examples, we observe that LWGC failure is accompanied by the existence of fractionally charged monopoles confined by flux tubes, where superextremal particles exist everywhere in the sublattice dual to the superlattice of fractional confined monopole charges. The confining flux tubes become light when the failure of the LWGC becomes more extreme, so monopoles deconfine in the limit where LWGC-violating particles become infinitely massive. We also identify similarities between these confined monopoles, non-invertible symmetries, and the Hanany-Witten effect.