Posted on 18 January 2017
Entropy is an essential quantity for diverse areas of physics such as thermodynamics, where it is central for the formulation of the second law, and information theory, where it characterises properties of data. However, the relation of these conceptually different notions of entropy is not yet fully understood. The Letter “Axiomatic Relation between Thermodynamic and Information-Theoretic Entropies” sheds light into this by connecting the macroscopic perspective of phenomenological thermodynamics to the microscopic view taken by information theorists and by statistical physicists. Such connection is established by identifying an axiomatic framework that allows for the derivation of entropy in both theories, putting them on an equal footing.