Cosmic p-branes

Abstract

We consider the metrics for cosmic strings and $p$-branes in spacetime dimension $N>4$, that is, we look for solutions to Einstein-Maxwell-Dilaton gravity in $N$-dimensions with boost symmetry in the $p$-directions along the brane. Focussing first in detail on the five dimensional uncharged cosmic string we discuss the solution, which turns out to have a naked singularity on the brane, as well as considering its Kaluza-Klein reduction. We show how singularities may be avoided with particular core models. We then derive the general uncharged $p$-brane solution in arbitrary dimension. Finally, we consider an Einstein-Maxwell-Dilaton action, with arbitrary value of the dilaton coupling parameter, deriving the solutions for electrically and magnetically charged branes, as well as a class of self-dual branes.