No abstract

We examine cylindrically symmetric solutions to the Einstein equations under the assumption of functional separability of the metric coefficients. Under the further assumption that the energymomentum tensor is of the form T: = Tf= --a(r,t), all such solutions, with their vacuum exteriors, are found. It is shown that the vacua cannot be matched smoothly onto a Robertson-Walker background.

The matching of Friedmann-Lemaftre-Robertson-Walker space-times onto a Kasner vacuum region is investigated. We apply the Darmois junction conditions to show that a spatially flat Einstein-de Sitter region can be joined smoothly to a special case of the Kasner vacuum space-time. This result suggests an intriguing cosmological model. PACS numberk): 98.80.H~

Errata Erratum: Nonstationary general-relativistic "strings" [Phys. Rev. D 40,3287 (1989)l