Infinite families of fracton fluids with momentum conservation

We construct infinite families of new universality classes of fracton hydrodynamics with momen-tum conservation, both with multipole conservation laws and/or subsystem symmetry. We explorethe effects of broken inversion and/or time-reversal symmetry at the ideal fluid level, along withmomentum relaxation. In the case of one-dimensional multipole-conserving models, we write downexplicit Hamiltonian systems realizing these new universality classes. Many of these hydrodynamicuniversality classes exhibit instabilities and will flow to new non-equilibrium fixed points.