Super-Penrose process due to collisions inside ergosphere

Abstract

If two particles collide inside the ergosphere, the energy in the centre of mass frame can be made unbound provided at least one of particles has a large negative angular momentum (A. A. Grib and Yu. V. Pavlov, Europhys. Lett. 101, 20004 (2013)). We show that the same condition can give rise to unbounded Killing energy of debris at infinity, i.e. super-Penrose process. Proximity of the point of collision to the black hole horizon is not required.Comment: 9 pages. Section V about collisions near the boundary of ergoregion added. To appear in IJMP