We use a connection between relativistic hydrodynamics and scalar field
theory to generate exact analytic solutions describing non-stationary
inhomogeneous flows of the perfect fluid with one-parametric equation of state
(EOS) p=p(ϵ). For linear EOS p=κϵ we obtain
self-similar solutions in the case of plane, cylindrical and spherical
symmetries. In the case of extremely stiff EOS (κ=1) we obtain
''monopole + dipole'' and ''monopole + quadrupole'' axially symmetric
solutions. We also found some nonlinear EOSs that admit analytic solutions.Comment: This is a contribution to the Proc. of the Seventh International
Conference ''Symmetry in Nonlinear Mathematical Physics'' (June 24-30, 2007,
Kyiv, Ukraine), published in SIGMA (Symmetry, Integrability and Geometry:
Methods and Applications) at http://www.emis.de/journals/SIGMA