  The observed dark matter phenomenon is attributed to the presence of a gas of
wormholes. We show that due to topological polarization effects the background
density of baryons generates non-vanishing values for wormhole rest masses. We
infer basic formulas for the scattering section between baryons and wormholes
and equations of motion. Such equations are then used for the kinetic and
hydrodynamic description of the gas of wormholes. In the Newtonian
approximation we consider the behavior of density perturbations and show that
at very large distances wormholes behave exactly like heavy non-baryon
particles, thus reproducing all features of CDM models. At smaller scales (at
galaxies) wormholes strongly interact with baryons and cure the problem of
cusps. We also show that collisions of wormholes and baryons lead to some
additional damping of the Jeans instability in baryons.
