Hi all,
tomorrow we'll have yesterday's group meeting --- Henrik Wilming from FU Berlin will give a talk at 4pm in H51. Title and abstract below.
Best,
-joe
Statistical ensembles without typicality ----------------------------------------- Maximum-entropy ensembles are key primitives in statistical mechanics from which thermodynamic properties can be derived. Over the decades, several approaches have been put forward in order to justify from minimal assumptions the use of these ensembles in statistical descriptions. I will explain a new approach to derive maximum-entropy ensembles taking a strictly operational perspective. To do that I will consider the set of possible transitions that a system can undergo together with an environment, when one only has partial information about the quantum states of both the system and its environment. The set of all these allowed transitions encodes thermodynamic laws and limitations on thermodynamic tasks as particular cases. Our main result is that the set of allowed transitions coincides with the one possible if both system and environment were assigned the maximum entropy state compatible with the partial information. This provides a new explanation for the overwhelming success of such ensembles and provides a derivation without relying on considerations of typicality or information-theoretic measures.