Anomalies and fermion zero modes on strings and domain walls

Effective actions for anomalous hydrodynamics

“…However, exploiting the inflow mechanism [53], all we need is a five dimensional Chern-Simons action which will serve to cancel the anomalous variation in (3.13) above. This is simply…”

“…4 The subscript of M 2n+1 denotes that the integral is over a manifold which is one dimension higher than the manifold in which the fluid lives. Here, we have found it useful to employ the anomaly inflow mechanism [53] (we refer the reader to the appendices of [30] for a recent review), i.e., viewing our anomalous field theory in d = 2n dimensions as the boundary dynamics of a bulk topological theory (in 2n + 1 dimensions), to guide us in writing covariant effective actions. So the physical part of the effective action in 2n dimensions is the boundary term arising from the transgression form, with the Chern-Simons pieces ensuring cancellation of the anomaly contributions between bulk and the boundary.…”

Global symmetries and 't Hooft anomalies in brane tilings

“…The baryonic symmetries with charge assignment Q I given by (22) can be realized with the gauge field V D5 on the D5-branes given by…”

“…We use hats to emphasize that fields are N × N matrices. The end points of open strings on face a couples to the non-dynamical gauge field V with the charge ±S a , and the charge of open string stretched on s ab is given by (22). We can regard edges as four-junctions of fivebranes and the boundary condition imposed on gauge fields on the four fivebranes is 3…”

Delocalization from anomaly inflow and intersecting brane dynamics

“…The gauge variation of this term cancels exactly the chiral anomaly. This mechanism is known as anomaly inflow, see [18] and [19].…”