The Secret Gauging of Flavor Symmetries in Noncommutative QFT

TL;DR

This paper demonstrates that flavor 't Hooft anomalies vanish in noncommutative field theories derived from string theory, due to hidden local flavor symmetries coupled to closed string modes, revealing a holographic encoding.

Contribution

It reveals that flavor symmetries in noncommutative QFTs are secretly local and explains the anomaly cancellation via coupling to closed string bulk modes.

Findings

Flavor 't Hooft anomalies vanish in noncommutative theories from string theory.

Closed string modes are off-shell in non-planar processes, encoding flavor symmetries holographically.

Example: SU(4) R-symmetry in N=4 D=4 NCSYM.

Abstract

We show that flavor 't Hooft anomalies automatically vanish in noncommutative field theories which are obtained from string theory in the decoupling limit. We claim that this is because the flavor symmetries are secretly local, because of coupling to closed string bulk modes. An example is the SU(4) R-symmetry of N=4 D=4 NCSYM. The gauge fields, along with all closed string bulk modes, are not on-shell external states but do appear as off-shell intermediate states in non-planar processes; these closed string modes are thereby holographically encoded in the NCFT.