Light Black Holes from Light

TL;DR

This paper discusses the theoretical possibility of black hole formation from light, emphasizing that quantum dissipative effects like vacuum polarization and Schwinger effect prevent such formation in realistic scenarios, though idealized processes could still produce tiny black holes.

Contribution

It highlights the role of quantum dissipative effects in preventing black hole formation from light in realistic conditions, contrasting with idealized theoretical models.

Findings

Quantum effects prevent black hole formation from light in realistic scenarios.

Idealized models can still produce microscopic black holes from photon collisions.

Schwinger effect dissipates energy, hindering black hole creation.

Abstract

Alvarez-Dominguez, Garay, Martin-Martinez, and Polo-Gomez have suggested that ``it is not possible to concentrate enough light to precipitate the formation of an event horizon. We argue that the dissipative quantum effects coming from the self-interaction of light (such as vacuum polarization) are enough to prevent any meaningful buildup of energy that could create a black hole in any realistic scenario,'' and ``the dissipation of energy via Schwinger effect alone is enough to prevent the formation of kugelblitze with radii ranging from $10^{-29}$ to $10^8$ m.'' While I agree that it is indeed highly implausible that black holes will form mainly from light in our actual universe, either naturally or by any foreseeable human activity, there are many idealized theoretical processes for forming black holes of any size down to near the Planck length (about $10^{-35}$ m) purely from photons, such as from colliding approximately plane-wave pulses, with only a small fraction of the energy escaping the black hole as scattered light or electron-positron pairs.