Vacuum and nonvacuum black holes in a uniform magnetic field
  We modify and generalize the known solution for the electromagnetic field when a vacuum, stationary, axisymmetric black hole is immersed in a uniform magnetic field to the case of nonvacuum black holes (of modified gravity) and determine all linear terms of the vector potential in powers of the magnetic field and the rotation parameter. 
Mustapha Azreg-A\"inou
gr-qc