Discrete gauge symmetries from (closed string) tachyon condensation

Understand

The study of discrete gauge symmetries in field theory and string theory is often carried out by embedding them into continuous symmetries.

• Many symmetries however do not seem to admit such embedding, for instance discrete isometries given by large diffeomorphisms in compactifications.
• We show that in the context of string theory even those symmetries can be embedded into continuous ones.
• This requires extending the system to a supercritical string theory configuration with extra dimensions, on which the continuous symmetry acts.