title: Enveloping branes and brane-world singularities.
abstract: The existence of envelopes is studied for systems of differential equations in connection with the method of asymptotic splittings which allows one to determine the singularity structure of the solutions. The result is applied to brane-worlds consisting of a 3-brane in a five-dimensional bulk, in the presence of an analog of a bulk perfect fluid parameterizing a generic class of bulk matter. We find that all flat brane solutions suffer from a finite-distance singularity contrary to previous claims. We then study the possibility of avoiding finite-distance singularities by cutting the bulk and gluing regular solutions at the position of the brane. Further imposing physical conditions such as finite Planck mass on the brane and positive energy conditions on the bulk fluid, excludes, however, this possibility as well.
authors.affiliation: Department of Physics, CERN-Theory Division, 1211 Geneva 23, Switzerland.
authors.forename: Ignatios
authors.initials: I
authors.lastname: Antoniadis
authors.affiliation: Department of Physics, CERN-Theory Division, 1211 Geneva 23, Switzerland.
authors.forename: Spiros
authors.initials: S
authors.lastname: Cotsakis
authors.affiliation: Research Group of Geometry, Dynamical Systems and Cosmology, Department of Information and Communication Systems Engineering, University of the Aegean, Karlovassi, 83 200 Samos, Greece.
authors.forename: Ifigeneia
authors.initials: I
authors.lastname: Klaoudatou