Unbound geodesics from the ergosphere and potential observability of debris from ultrahigh energy particle collisions

Abstract

Particle collisions in black hole ergoregions may result in extremely high center of mass energies that could probe new physics if escape to infinity were possible. Here we show that some geodesics at high inclinations to the equatorial plane may be unbound. Hence a finite flux of annihilation debris is able to escape, especially in the case of near-extremal Kerr black holes and if the Penrose process plays a role. For a class of Penrose processes, we show that the Wald inequalities are satisfied, allowing the Penrose process to have a key role in high energy ejection. Hence the possibility of observing new physics effects from a black hole accelerator at unprecedentedly high particle collision energies remains a tantalizing, if futuristic, experimental vision.

6 pages and 2 figures

References in corpus (5)

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• Emergent Flux from Particle Collisions Near a Kerr Black Hole
• Collision of two general geodesic particles around a Kerr black hole
• Probing Dark Matter with AGN Jets
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Cited by in corpus (10)

• Black holes as particle accelerators: a brief review
• Ultra-high-energy debris from the collisional Penrose process
• The Collisional Penrose Process
• Are black holes totally black?
• Disclosing connections between black holes and naked singularities: Horizon remnants, Killing throats and bottlenecks
• Unbounded energies of debris from head-on particle collisions near black holes
• Repulsive gravity effects in horizon formation. Horizon remnants in naked singularities
• Timescale for trans-Planckian collisions in Kerr spacetime
• Geodesics dynamics in the Linet-Tian spacetime with Lambda>0
• Neutral particle collisions near Gibbons-Maeda-Garfinkle-Horowitz-Strominger black holes after shadow observations