Holographic Charged Fluid with Anomalous Current at Finite Cutoff Surface in Einstein-Maxwell Gravity

TL;DR

This paper extends the holographic charged fluid with anomalous current to finite cutoff surfaces in Einstein-Maxwell gravity, analyzing how transport coefficients depend on the cutoff and revealing a universal shear viscosity to entropy density ratio.

Contribution

It generalizes the holographic charged fluid with anomalies to finite cutoff surfaces and derives the cutoff-dependent transport coefficients using gravity/fluid correspondence.

Findings

Dual fluid is non-conformal with zero bulk viscosity.

Shear viscosity to entropy density ratio remains universal at 1/4π.

Cutoff-dependent corrections affect the chiral magnetic conductivity.

Abstract

The holographic charged fluid with anomalous current in Einstein-Maxwell gravity has been generalized from the infinite boundary to the finite cutoff surface by using the gravity/fluid correspondence. After perturbing the boosted Reissner-Nordstrom (RN)-AdS black brane solution of the Einstein-Maxwell gravity with the Chern-Simons term, we obtain the first order perturbative gravitational and Maxwell solutions, and calculate the stress tensor and charged current of the dual fluid at finite cutoff surfaces which contains undetermined parameters after demanding regularity condition at the future horizon. We adopt the Dirichlet boundary condition and impose the Landau frame to fix these parameters, finally obtain the dependence of transport coefficients in the dual stress tensor and charged current on the arbitrary radical cutoff $r_c$. We find that the dual fluid is not conformal, but it has vanishing bulk viscosity, and the shear viscosity to entropy density ratio is universally $1/4\pi$. Other transport coefficients of the dual current turns out to be cutoff-dependent. In particular, the chiral vortical conductivity expressed in terms of thermodynamic quantities takes the same form as that of the dual fluid at the asymptotic AdS boundary, and the chiral magnetic conductivity receives a cutoff-dependent correction which vanishes at the infinite boundary.