Are there hyperentropic objects ?

TL;DR

This paper argues that hyperentropic objects are unlikely to be emitted in Hawking radiation due to their slow formation, thus upholding entropy bounds and the generalized second law of thermodynamics.

Contribution

It demonstrates that hyperentropic objects cannot be produced rapidly in Hawking radiation, resolving a potential loophole in entropy bounds.

Findings

Hyperentropic objects form extremely slowly, making their emission negligible.

Weakly self-gravitating hyperentropic objects are ruled out by thermodynamic laws.

Some strongly self-gravitating hyperentropic objects are also excluded.

Abstract

By treating the Hawking radiation as a system in thermal equilibrium, Marolf and R. Sorkin have argued that hyperentropic objects (those violating the entropy bounds) would be emitted profusely with the radiation, thus opening a loophole in black hole based arguments for such entropy bounds. We demonstrate, on kinetic grounds, that hyperentropic objects could only be formed extremely slowly, and so would be rare in the Hawking radiance, thus contributing negligibly to its entropy. The arguments based on the generalized second law of thermodynamics then rule out weakly self-gravitating hyperentropic objects and a class of strongly self-gravitating ones.