Role of shear in general relativistic cosmological and stellar models

Feb, 1982
10 pages
Published in:
  • Phys.Rev.D 27 (1983) 1209-1218

Citations per year

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Abstract: (APS)
We investigate the class of shear-free expanding (or contracting) irrotational perfect fluids obeying an equation of state p=p(μ) and satisfying the field equations of general relativity. It is shown that these space-times are either Friedmann-Robertson-Walker, or spherically symmetric Wyman solutions, or a special class of plane-symmetric models. This last class, which is given in exact form, is apparently new; the metrics are locally either spatially or temporally homogeneous. We show that the spherically symmetric Wyman solutions and the new class of plane-symmetric models are inconsistent with the additional requirement of a comoving surface of zero pressure, and thereby obtain a coordinate-free proof and a generalization of a result of Mansouri, concerning shear-free spherically symmetric gravitational collapse. Some properties of our solutions, and further generalizations of our results, are considered.