Flux Quantization on M5-branes
Grigorios Giotopoulos, Hisham Sati, Urs Schreiber
TL;DR
This work reframes flux quantization on M5-branes as a global completion problem within twisted co-Homotopy by leveraging super-spacetime Bianchi identities and the super-embedding formalism. It provides a streamlined derivation of the M5 worldvolume 3-form flux H_3 from 1/2BPS super-immersions and shows that self-duality constraints are absorbed into super-Bianchi identities, enabling a complete on-shell field content without ad hoc global data. Adopting Hypothesis H, the authors classify admissible flux laws by a twisted differential cohomology theory whose rational type matches the quaternionic Hopf fibration, yielding Skyrmion-like worldvolume solitons and, for open M5-branes, anyonic boundary states via co-Homotopy. The framework unifies local gauge potentials with global flux data through concordances, and predicts rich topological features (e.g., configurational moduli, braid-group statistics) that connect M5-brane physics to strongly coupled quantum systems and holography. Overall, the paper advances a cohesive, geometrically rigorous picture in which M5-brane flux quantization is governed by non-abelian, twisted cohomological structures rather than classical abelian cohomology alone.
Abstract
We highlight the need for global completion of the field content in the M5-brane sigma-model analogous to Dirac's charge/flux quantization, and we point out that the superspace Bianchi identities on the worldvolume and on its ambient supergravity background constrain the M5's flux-quantization law to be in a non-abelian cohomology theory rationally equivalent to a twisted form of co-Homotopy. In order to clearly bring out this subtle point we give a streamlined re-derivation of the worldvolume 3-flux via M5 "super-embeddings". Finally, assuming the flux-quantization law to actually be in co-Homotopy ("Hypothesis H") we show how this implies Skyrmion-like solitons on general M5-worldvolumes and (abelian) anyonic solitons on the boundaries of "open M5-branes" in heterotic M-theory.
