The charged McVittie spacetime
  The two-parameter charged McVittie solution of the Einstein equations is revisited and its apparent horizons are discussed and located numerically (for the extremal case, analytically). According to the parameter values, this spacetime can be interpreted as a black hole, or a spacelike naked singularity, in a spatially homogeneous and isotropic universe. 
Valerio Faraoni, Andres F. Zambrano Moreno and Angus Prain
gr-qc