On freeze-out problem in relativistic hydrodynamics
arXiv:0810.2262 · doi:10.1134/S1063778809070187
Abstract
A finite unbound system which is equilibrium in one reference frame is in general nonequilibrium in another frame. This is a consequence of the relative character of the time synchronization in the relativistic physics. This puzzle was a prime motivation of the Cooper--Frye approach to the freeze-out in relativistic hydrodynamics. Solution of the puzzle reveals that the Cooper--Frye recipe is far not a unique phenomenological method that meets requirements of energy-momentum conservation. Alternative freeze-out recipes are considered and discussed.
6 pages, 2 figures, references are corrected and updated, to be published in the issue of Phys. Atom. Nucl. dedicated to S.T. Belyaev on the occasion of his birthday