Symmetry Inheritance and Jebsen-Birkhoff Theorem
  It is known that the Jebsen-Birkhoff theorem is valid for vacuum solutions to Einstein's equation, as well as some of its generalizations. Using symmetry inheritance properties we investigate in detail the additional constraints that fields have to satisfy in order to allow the Jebsen-Birkhoff theorem in the non-vacuum cases of a wide class of gravitational field equations. 
Benjamin Mesi\'c, Ivica Smoli\'c
gr-qc