Electromagnetic Excitation of Rotating Black Holes and Relativistic Jets
  We show that electromagnetic excitations of rotating black holes can lead to the appearance of narrow singular beams which break up the black hole horizon forming a tube-like region which connects the interior and exterior. It is argued that this effect may be at the origin of jet formation. 
A.Burinskii, E. Elizalde, S.R. Hildebrandt and G. Magli