XI Encontro Nacional de Astronomia e Astrofísica


Charged solutions in three-dimensional Brans-Dicke gravity theories

Óscar J. C. Dias
CENTRA, Departamento de Física, Instituto Superior Técnico, Av. Rovisco Pais 1, 1096 Lisboa,

José P. S. Lemos

Resumo

We obtain static and rotating charged solutions of a Einstein-Maxwell-Dilaton theory of the Brans-Dicke type in (2+1)-dimensions. The theory is specified by three fields, the dilaton f, the graviton gµ and the electromagnetic field Fmn , and two parameters, the cosmological constant D and the Brans-Dicke parameter w. We analyse purely electric and purely magnetic solutions.
The purely electrical solutions have eight different cases, of which one distinguishes
as special, string theory (w=-1), electrically charged three dimensional general relativity w=±¥  and a theory related (through dimensional reduction) to four dimensional general relativity with one Killing vector (w=0). For each range of w we find the ADM mass, the angular momentum and electric charge of the solutions. We also analyse the causal and geodesic structure of the electrically charged solutions.
The purely magnetic solutions do not contain black holes. This result was already known for the magnetically charged three dimensional general relativity (w=±¥). The magnetic spacetime solutions are geodesically complete and particle-like.


Grupo de Astronomia da Universidade da Madeira - 2001