Bootstrapping microcanonical ensemble in classical system

Is microcanonical ensemble stable?

No, in a rigorous sense specified below.

Entanglement of a microcanonical ensemble

We replace time-averaged entanglement by ensemble-averaged entanglement and derive a simple expression for the latter. We show how to calculate the ensemble average for a two-spin system and for the JaynesCummings model. In both cases the time-dependent entanglement is known as well so that one can verify that the time average coincides with the ensemble average.

A generalized quantum microcanonical ensemble

We discuss a generalized quantum microcanonical ensemble. It describes isolated systems that are not necessarily in an eigenstate of the Hamilton operator. Statistical averages are obtained by a combination of a time average and a maximum entropy argument to resolve the lack of knowledge about initial conditions. As a result, statistical averages of linear observables coincide with values obtai...

Non-Extensivity of the Configurational Density Distribution in the Classical Microcanonical Ensemble

We show that the configurational probability distribution of a classical gas always belongs to the q-exponential family. One of the consequences of this observation is that the thermodynamics of the configurational subsystem is uniquely determined up to a scaling function. As an example we consider a system of non-interacting harmonic oscillators. In this example, the scaling function can be de...

Genuine phase diffusion of a Bose-Einstein condensate in the microcanonical ensemble: A classical field study