Ultra-high-energy head-on collisions without horizons or naked singulrities: general approach

Abstract

Recently, alternatives to the Bañados, Silk and West (BSW) effect were proposed which are (i) due to the existence of naked singularities instead of the horizon, (ii) require neither horizon nor naked singularity. We reveal the main features of such alternatives in a model-independent way. The metric should be close to that of the extremal black hole but the horizon should not form. Then, one can gain unbound the energy E_{c.m.} in the centre of mass frame due to head-on collision of particles near the would-be horizon. The energy measured at infinity can also be unbound. If instead of particles self-gravitating shells collide, the underlying reason leading to unbound E_{c.m.} is the same.

13 pages. Refs. 11, 20 added. To appear in PRD

References in corpus (8)

• Collisional Penrose process near the horizon of extreme Kerr black holes
• Acceleration of particles by black holes -- general explanation
• Acceleration of colliding shells around a black hole: Validity of the test particle approximation in the Banados-Silk-West process
• Quasi-black holes: definition and general properties
• Ultra-high energy particle collisions in a regular spacetime without blackholes or naked singularities
• On the energy of particle collisions in the ergosphere of the rotating black holes
• Ultra-high energy collision with neither black hole nor naked singularity
• Acceleration of particles by quasiblack holes

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• Center of mass energy of colliding electrically neutral particles and super-Penrose process
• Collisional Penrose Process in Rotating Wormhole Spacetime
• Enhanced Line Signals from Annihilating Kaluza-Klein Dark Matter
• Super-Penrose process and rotating wormholes
• High energy particle collisions in static, spherically symmetric black-hole-like wormholes
• Unbounded energies of debris from head-on particle collisions near black holes
• Rotation as an origin of high energy particle collisions
• Is there a trade-off relation between efficiency and power in a collisional Penrose process in an extreme Reissner-Nordström spacetime?