  Thermodynamics and dynamics of a classical two-dimensional system with
dipole-like isotropic repulsive interactions are studied systematically using
extensive molecular dynamics (MD) simulations supplemented by appropriate
theoretical approximations. This interaction potential, which decays as an
inverse cube of the interparticle distance, belongs to the class of very soft
long-ranged interactions. As a result, the investigated system exhibits certain
universal properties that are also shared by other related soft-interacting
particle systems (like, for instance, the one-component plasma and weakly
screened Coulomb systems). These universalities are explored in this article to
construct a simple and reliable description of the system thermodynamics. In
particular, Helmholtz free energies of the fluid and solid phases are derived,
from which the location of the fluid-solid coexistence is determined. The
quasi-crystalline approximation is applied to the description of collective
modes in dipole fluids. Its simplification, previously validated on strongly
coupled plasma fluids, is used to derive explicit analytic dispersion relations
for the longitudinal and transverse wave modes, which compare satisfactory with
those obtained from direct MD simulations in the long-wavelength regime. Sound
velocities of the dipole fluids and solids are derived and analyzed.
