title: Optimizing entropy bounds for macroscopic systems.
abstract: The universal bound on specific entropy (entropy-to-energy ratio) was originally inferred from black hole thermodynamics. Here we show from classical thermodynamics alone that for a system at fixed volume or fixed pressure, the entropy-to-energy ratio S/E has a unique maximum, (S/E)(max). A simple argument from quantum dynamics allows one to set a model-independent upper bound on (S/E)(max) which is usually much tighter than the universal bound. We illustrate with two examples.
authors.affiliation: Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Jacob D
authors.initials: JD
authors.lastname: Bekenstein