The collisional Penrose process

Abstract

Shortly after the discovery of the Kerr metric in 1963, it was realized that a region existed outside of the black hole's event horizon where no time-like observer could remain stationary. In 1969, Roger Penrose showed that particles within this ergosphere region could possess negative energy, as measured by an observer at infinity. When captured by the horizon, these negative energy particles essentially extract mass and angular momentum from the black hole. While the decay of a single particle within the ergosphere is not a particularly efficient means of energy extraction, the collision of multiple particles can reach arbitrarily high center-of-mass energy in the limit of extremal black hole spin. The resulting particles can escape with high efficiency, potentially serving as a probe of high-energy particle physics as well as general relativity. In this paper, we briefly review the history of the field and highlight a specific astrophysical application of the collisional Penrose process: the potential to enhance annihilation of dark matter particles in the vicinity of a supermassive black hole.

Dark Matter Candidates with Dark Energy Interiors Determined by Energy Conditions

“…Geometry of rotating objects includes ergoregions where processes of extraction of rotational energy can occur (see, e.g., a topical review in Reference [42]). Spinning G-lump can have two ergospheres and ergoregion between them, or one ergosphere and ergoregion beyond it [38].…”

Fifty Years of Energy Extraction from Rotating Black Hole: Revisiting Magnetic Penrose Process

“…Thus, Penrose process was very ingenious and interesting but it was astrophysically not viable to power high energy sources. Then, various variants of the process were considered [28][29][30][31][32][33][36][37][38] but not of any consequence or avail.…”

Pure electric Penrose and super-Penrose processes in the flat spacetime

“…Another aim of the present work is to evaluate the efficiency η of the PP. Near rotating uncharged black holes it is quite modest [7], [9], [10] - [12]. However, it was noticed earlier that near charged black holes electromagnetic interaction favours PP [13], [14].…”

“…In case (ii) the efficiency of the process is essentially restricted. The collisional version improves the situation but anyway η remains bounded (see [7], [18] and references therein).…”