Anomalous conductivities in the holographic Stückelberg model

Abstract

We have studied a massive U(1) gauge holographic model with pure gauge and mixed gauge-gravitational Chern-Simons terms. The full backreaction of the gauge field on the metric tensor has been considered in order to explore the vortical and energy transport sector. The background solution has been computed numerically. On this background, we have considered the fluctuation of the fields and evaluated the different correlators. We have found that all the correlators depend on the mass of the gauge field. Correlators such as the current-current one, 〈JxJx〉, which were completely absent in the massless case, in the presence of a finite gauge boson mass start picking up some finite value even at zero chemical potential. Similarly, the energy-current correlator, 〈T0xJx〉, which was also absent in the massless theory, has now a non-vanishing value but for finite values of the chemical potential. Our findings for the chiral vortical conductivity, σV, and the chiral magnetic/vortical conductivity of energy current, {sigma}_B^{varepsilon }={sigma}_V^{varepsilon } , are completely new results. In addition to this, we have found that these anomalous transport coefficients depend linearly both on the pure Chern-Simon coupling, κ, and on the mixed gauge-gravity Chern-Simon coupling, λ. One of the results that we would like to highlight is that it’s not just κ that contributes to the σB but there is an additional contribution from λ as well unlike the previous studies.