1997/10/09 by K. A. Bronnikov, V. D. Ivashchuk, V. N. Melnikov · 1 citation
Physics and Astronomy · #gr-qc
published as Grav.Cosmol. 3 (1997) 203-212 · 10 pages, Latex, to be published in Grav.& Cosmol. v.3, No.3 (1997)
arxiv created 1997/10/09 · arxiv updated 2009/11/30
A multidimensional model with (at most) one curved factor space and n Ricci-flat internal spaces is considered, with arbitrary numbers of dilatonic scalar fields and antisymmetric forms of both electric and magnetic types, associated with p-branes in theories like M-theory. The problem setting covers, in particular, homogeneous cosmologies, static, spherically symmetric and Euclidean models. Exact solutions are obtained when the p-brane dimensions and the dilatonic couplings obey orthogonality conditions in minisuperspace. Conditions for black hole and wormhole existence among static models are formulated. For black holes, a kind of no-hair theorem, leading to F-form selection, is obtained; it is shown that even in spaces with multiple times a black hole may only exist with its unique, one-dimensional time; infinite Hawking temperature is explicitly shown to imply a curvature singularity at an assumed horizon, and such cases among extreme black-hole solutions are indicated.