More on nonrelativistic diffeomorphism invariance

Certain aspects of nonrelativistic diffeomorphisms in $2+1$ dimensions are investigated. These include a nonrelativistic limit of some relativistic actions in three dimensions, the Seiberg–Witten map, a modification of the viscosity tensor in particular due to a nonuniform magnetic field, a redefinition of background fields, and $1/R$ terms on Riemann surfaces of constant curvature.