On the Status of Highly Entropic Objects

TL;DR

This paper investigates whether proposed entropy bounds for physical systems—the Bekenstein bound and the holographic bound—are violated by highly entropic objects that might be radiated by black holes. It argues that the thermodynamics of black holes at Hawking temperature, via free energy considerations F = E − T_BH S and the principle of detailed balance, generically favors the emission of such objects, preventing violations of the generalized second law. The authors generalize the analysis beyond Schwarzschild black holes to abstract absorption processes and to the holographic bound, showing that negative free energy implies robust Hawking emission in multiple regimes. They discuss potential observational consequences, including constraints from black hole mass loss and conceivable experimental limits on hypothetical highly entropic objects. Overall, the work reveals a loophole in entropy-bounding arguments and highlights possible empirical tests of fundamental bounds.

Abstract

It has been proposed that the entropy of any object must satisfy fundamental (holographic or Bekenstein) bounds set by the object's size and perhaps its energy. However, most discussions of these bounds have ignored the possibility that objects violating the putative bounds could themselves become important components of Hawking radiation. We show that this possibility cannot a priori be neglected in existing derivations of the bounds. Thus this effect could potentially invalidate these derivations; but it might also lead to observational evidence for the bounds themselves.