Critical assessment of some inhomogeneous pressure Stephani models

  title={Critical assessment of some inhomogeneous pressure Stephani models},
  author={Adam P. Balcerzak and Mariusz P. Da̧browski and Tomasz Denkiewicz and David Polarski and Denis Puy},
  journal={Physical Review D},
We consider spherically symmetric inhomogeneous pressure Stephani universes, with the center of symmetry being our location. The main feature of these models is that comoving observers do not follow geodesics. In particular, comoving perfect fluids necessarily have a radially dependent pressure. We consider a subclass of these models characterized by some inhomogeneity parameter $\ensuremath{\beta}$. We show also that the velocity of sound of comoving perfect fluids, like the (effective… 

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