Matching of Friedmann-Lemaître-Robertson-Walker and Kasner cosmologies (Q2752488)

In this paper, the authors investigate ``the matchings of Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetimes onto a Kasner vacuum region'' when both metrics are written in a cylindrically symmetric form. As the authors note it is known [\textit{C. C. Dyer}, \textit{S. Landry} and \textit{E. G. Shaver}, Phys. Rev. D (3) 47, 1404 ff. (1993)] that a spatially flat FLRW metric can be joined to Kasner, and, in this paper, the authors show that an open FLRW spacetime can be joined to Kasner. The matching is done using Darmois junction conditions. ``An interesting feature of this matching is the fact that the matching hypersurface is not a coordinate hypersurface...''. In addition, the authors generalize the Kasner solution to a solution with non-zero cosmological constant, write this generalized metric in cylindrically symmetric form and then match to an FLRW metric. They note that the presence of a nonzero cosmological constant has no significant effect on the matching.