Intersecting electric and magnetic p-branes: Spherically symmetric solutions

We consider a D-dimensional self-gravitating spherically symmetric configur ation of a generalized electro-magnetic n-form F and a dilatonic scalar fie ld, admitting an interpretation in terms of intersecting p-branes. For theo ries with additional (internal) times, selection rules are obtained, which obstruct the existence of p-branes in certain subspaces. General static sol utions are obtained under a specific restriction on the model parameters, w hich corresponds to certain orthogonality relations in the target-space of effective fields. More special families of solutions (with equal charges fo r some of the F-field components) are found with weakened restrictions on t he input parameters. Black-hole solutions are determined, and it is shown t hat in the extreme limit the Hawking temperature may tend to zero, a finite value, or infinity, depending on the p-brane intersection dimension. A kin d of no-hair theorem is obtained, claiming that black holes cannot coexist with a quasiscular component of the F-field.