title: Density-curvature response and gravitational anomaly.
abstract: We study constraints imposed by the Galilean invariance on linear electromagnetic and elastic responses of two-dimensional gapped systems in a background magnetic field. Exact relations between response functions following from the Ward identities are derived. In addition to the viscosity-conductivity relations known in the literature, we find new relations between the density-curvature response and the thermal Hall response.
authors.affiliation: Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA.
authors.forename: Andrey
authors.initials: A
authors.lastname: Gromov
authors.affiliation: Department of Physics and Astronomy and Simons Center for Geometry and Physics, Stony Brook University, Stony Brook, New York 11794, USA.
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Abanov