In statistical mechanics, the ensemble average is defined as the mean of a quantity that is a function of the micro-state of a system (the ensemble of possible states), according to the distribution of the system on its micro-states in this ensemble.
Since the ensemble average is dependent on the ensemble chosen, its mathematical expression varies from ensemble to ensemble. However, the mean obtained for a given physical quantity doesn't depend on the ensemble chosen at the thermodynamic limit.
Read more about Ensemble Average: Ensemble Average in Other Ensembles
Famous quotes containing the word average:
“... to be successful a person must attempt but one reform. By urging two, both are injured, as the average mind can grasp and assimilate but one idea at a time.”
—Susan B. Anthony (1820–1906)