Intersecting Electric and Magnetic p-branes: Spherically Symmetric Solutions

Abstract

We consider a D-dimensional self-gravitatingspherically symmetric configuration of a generalizedelectro-magnetic n-form F and a dilatonic scalar field,admitting an interpretation in terms of intersecting p-branes. For theories with additional(internal) times, selection rules are obtained, whichobstruct the existence of p-branes in certain subspaces.General static solutions are obtained under a specific restriction on the model parameters, whichcorresponds to certain orthogonality relations in thetarget-space of effective fields. More special familiesof solutions (with equal charges for some of the F-field components) are found with weakenedrestrictions on the input parameters. Black-holesolutions are determined, and it is shown that in theextreme limit the Hawking temperature may tend to zero, a finite value, or infinity, depending on thep-brane intersection dimension. A kind of no-hairtheorem is obtained, claiming that black holes cannotcoexist with a quasiscalar component of theF-field.