We show that, for Galilean invariant quantum Hall states, the Hall viscosity appears in the electromagnetic response at finite wave numbers q. In particular, the leading q dependence of the Hall conductivity at small q receives a contribution from the Hall viscosity. The coefficient of the q^2 term in the Hall conductivity is universal in the limit of strong magnetic field.
@article{arxiv.1109.2651,
title = {Hall Viscosity and Electromagnetic Response},
author = {Carlos Hoyos and Dam Thanh Son},
journal= {arXiv preprint arXiv:1109.2651},
year = {2012}
}