%0 Journal Article
%T Lorentzian manifolds isometrically embeddable in L^N
%A Olaf M¨šller
%A Miguel S¨˘nchez
%J Mathematics
%D 2008
%I arXiv
%X We characterize those spacetimes which admit a isometric (or conformal) embedding in some Lorentz-Minkowski space L^N. In particular, any globally hyperbolic spacetime can be isometrically embedded in L^N. This is proven by a result of its own interest: the construction of a smooth time function whose gradient is bounded away from zero -and, thus, an orthogonal global splitting of the spacetime with bounded lapse. The role of the so-called "folk problems on smoothability" is stressed.
%U http://arxiv.org/abs/0812.4439v4