A. Krasinski et al., ON THE THERMODYNAMICAL INTERPRETATION OF PERFECT FLUID SOLUTIONS OF THE EINSTEIN EQUATIONS WITH NO SYMMETRY, Journal of mathematical physics, 38(5), 1997, pp. 2602-2610
The Gibbs-Duhem equation dU + pdV = TdS imposes restrictions on the pe
rfect fluid solutions of Einstein equations that have a one-dimensiona
l symmetry group or no symmetry at all. In this paper, we investigate
the restrictions imposed on the Stephani Universe and on the two class
es of models found by Szafron. Upon the Stephani Universe and the beta
'not equal 0 class of Szafron symmetries are forced. We find the most
general subcases of the beta'=0 model of Szafron that are consistent w
ith the Gibbs-Duhem equation and have no symmetry. (C) 1997 American I
nstitute of Physics.