Jps. Lemos et Os. Ventura, PLANAR AND AXISYMMETRICAL WALLS IN GENERAL-RELATIVITY, A COMPARISON, Journal of mathematical physics, 35(7), 1994, pp. 3604-3611
Through Birkhoff's theorem it is shown that there are three planar wal
ls with time-independent surface energy density, the Taub, Kasner, and
Vilenkin walls. Under certain conditions Vilenkin's planar wall is un
ique. In analogy with the planar case a family of axisymmetric walls a
re analyzed and compared.