Entropy bounds and black hole remnants.

摘要: We rederive the universal bound on entropy with help of black holes while allowing for Unruh-Wald buoyancy. consider a box full lowered toward and then dropped into Reissner-Nordstr\"om hole in equilibrium thermal radiation. avoid approximation that buoyant pressure varies slowly across box, compute force exactly. find, agreement independent investigations, neutral point generically lies very near horizon. A consequence is generic case restriction neither necessary nor sufficient enforcement generalized second law. Another buoyancy makes only negligible contribution to energy bookkeeping, so original recovered if law assumed hold. The number particle species does not figure bound, has caused some perplexity. demonstrate by explicit calculation that, an arbitrarily large species, indeed satisfied cavity radiation thermodynamic regime, provided vacuum energies are included. also show directly D-dimensional space respects regardless value D. As application we it strongly restricts information capacity posited remnants, they cannot serve resolve paradox.