Finite energy electric monopoles in an extended theory of gravitation

We present a one-parameter family of extended Einstein--Maxwell Lagrangians in which an antisymmetric tensor field is nonlinearly coupled to both the gravitational and electromagnetic fields. We show that for arbitrary, positive values of the relevant parameter, the theory admits exact, static spherically symmetric solutions with everywhere finite electric field density and energy density. Asymptotically, the solutions are indistinguishable from the Reissner--Nordstrom solution in general relativity. In addition, we show that a corrected form of the exact solution in the nonsymmetric Kaluza--Klein theory presented in an earlier paper provides a special case of the family of solutions described above