1205.4410 (O. B. Zaslavskii)

On energetics of particle collisions near black holes: BSW effect versus Penrose process    [PDF]

O. B. Zaslavskii

If two particles collide near the horizon of a rotating or charged black hole, under certain conditions the energy E_{c.m.} in the centre of mass frame can grow without limit (the so-called BSW effect). Let collision produce two another particles. We show that for an outgoing particle detected by a distant observer, there exist upper bounds on the mass and energy E_{out}. For a static charged black hole, the dependence of E_{out} on the energy E_{in} of an ingoing "critical" particle (responsible for the BSW effect) is decreasing. For neutral rotating black holes it is increasing but for the high-energy particles the ratio E_{out}/E_{in}<1. As a result, the BSW effect is inconsistent with the Penrose process. The obtained results suggest astrophysical limits on possibility of observation of the products of the BSW effect. From the other hand, collisions with finite E_{c.m.} can produce particles with unbound ratio E_{out}/E_{in}.

View original: http://arxiv.org/abs/1205.4410