  Low-energy dynamics of many-body fracton excitations necessary to describe
topological defects should be governed by a novel type of hydrodynamic theory.
We use a Poisson bracket approach to systematically derive hydrodynamic
equations from conservation laws of scalar theories with fracton excitations.
We study three classes of theories. In the first class we introduce a general
action for a scalar with a shift symmetry linear in the spatial coordinates,
whereas the second one correspond with a complex scalar, while the third class
serves as a toy model for disclinations and dislocations propagating along the
Burgers vector. We apply our construction to study hydrodynamic fluctuations
around equilibrium states and derive the dispersion relations of hydrodynamic
modes.
