Time dependent supergravity solutions in arbitrary dimensions

By directly solving the equations of motion we obtain the time dependentsolutions of supergravities with dilaton and a $q$-form field-strength inarbitrary dimensions. The metrics are assumed to have the symmetries ISO($p+1$)$\times$ SO($d-p-2,1$) and can be regarded as those of the magnetically chargedEuclidean or space-like branes. When we impose the extremality condition, wefind that the magnetic charges of the branes become imaginary and thecorresponding real solutions then represent the E$p$-branes of type II$^\ast$theories (for the field-strengths belonging to the RR sector). On the otherhand, when the extremality condition is relaxed we find real solutions in typeII theories which resemble the solutions found by Kruczenski-Myers-Peet. In$d=10$ they match exactly. We point out the relations between the solutionsfound in this paper and those of Chen-Gal'tsov-Gutperle in arbitrarydimensions. Although there is no extremal limit for these solutions, we findanother class of solutions, which resemble the solutions in the extremal casewith imaginary magnetic charges and the corresponding real solutions can beregarded as the non-BPS E$p$-brane solutions of type II$^\ast$ theories (forthe field-strengths in RR sector).Comment: 21 pages, LaTeX, no figures, v2: comparisons of KMP SNS-brane solutions are given, references added, v3: JHEP versio