Weyl anomaly induced transport in hydrodynamics

TL;DR

This paper demonstrates that the Weyl (trace) anomaly induces a novel non-dissipative vector current in accelerated relativistic fluids, linking quantum anomalies to hydrodynamic transport phenomena.

Contribution

It extends hydrodynamic anomaly matching to include the trace anomaly, deriving a new transport coefficient and revealing a novel class of anomaly-induced transport effects.

Findings

Weyl anomaly causes a new non-dissipative vector current in fluids.

The second-order transport coefficient is fixed by the anomaly.

Electric and magnetic fields induce charge density and transverse currents.

Abstract

We show that the Weyl (trace) anomaly gives rise to a new non-dissipative vector current in accelerated relativistic fluids. The anomaly uniquely fixes the second-order transport coefficient governing the coupling between the electromagnetic field and the fluid acceleration. We derive this result by extending hydrodynamic anomaly matching to include the trace anomaly, and independently reproduce it in boundary quantum field theory by treating the Rindler horizon of an accelerated observer as an effective boundary. From the boundary perspective, the electric- and magnetic-field sectors correspond to screening and vacuum magnetization effects near the boundary. In the local rest frame, the electric-field contribution induces an additional charge density, while the magnetic-field contribution generates a transverse current with a Nernst-like, more generally thermomagnetic Hall-like, tensor structure. Our results reveal a new class of anomaly-induced transport governed by the trace anomaly.