1202.0565 (O. B. Zaslavskii)

Acceleration of particles by black holes as a result of deceleration:
ultimate manifestation of kinematic nature of BSW effect    [PDF]

O. B. Zaslavskii

The recently discovered so-called BSW effect consists in the unbound growth
of the energy E_{c.m.} in the centre of mass frame of two colliding particles
near the black hole horizon. We consider a new type of the corresponding
scenario when one of two particles ("critical") remains at rest near the
horizon of the charged near-extremal black hole due to balance between the
attractive and repulsion forces. The other one hits it with a speed close to
that of light. This scenario shows in a most pronounced way the kinematic
nature of the BSW effect. In the extremal limit, one would gain formally
infinite E_{c.m.} but this does not happen since it would have require the
critical massive particle to remain at rest on the null horizon surface that is
impossible.

View original: http://arxiv.org/abs/1202.0565