Transport properties of fluids characterize the way fluids respond to perturbations. For instance, the shear viscosity of a fluid can be thought of as describing its (linear) response to metric perturbations, electric conductivity describes the response of a fluid to an external electric field etc. If the underlying theory describing a fluid is anomalous, i.e., its symmetries are spoiled by quantum effects, then the fluid will respond non trivially to vorticity and an external (flavor) magnetic field. The study of the anomalous response of normal fluids to perturbations has been extensively studied in the literature.
Superfluids are special types of fluids in which extra quantum excitations modify the fluid behavior so that it allows for dissipationless configurations. The standard analysis of the relation between anomalies and transport does not give clear predictions when applied to superfluids. In a recent paper I. Amado, N. Lisker and A. Yarom have shown that for particular kinds of superfluids—those that have an alternate (holographic) description, the transport coefficients associated with vorticity and a magnetic field are fixed uniquely by the anomaly. It remains to be seen if this somewhat mysterious relation holds for all types of superfluids or is a unique features of holographic ones.