Explain the exact notion of an ensemble

[h0dgey84bc]

Hi, can someone please explain the exact notion of an ensemble to me please?

In the canonical ensemble, how do ensembles exchange energy between one another?
what is the significance of keeping the temperature fixed?

thanks

 

[Andrew Mason]

Hi, can someone please explain the exact notion of an ensemble to me please?

In the canonical ensemble, how do ensembles exchange energy between one another?
what is the significance of keeping the temperature fixed?

I understand that the canonical ensemble that just elected the new Pope held lively exchanges. But you might want to check this out:

http://en.wikipedia.org/wiki/Canonical_ensemble

AM

 

[dextercioby]

The canonical ensemble assumes a heat reservoir for each statistical system from the ensemble and the continuous (thermal) energy change between the reservoir & the system insures constant temperature.

The 2 constraints which characterize the canonical ensemble are:

*normalization for the probability density/the density operator
*fixing of the average of the classical/quantum hamiltonian.

Then apply the axioms and get the entropy...

Daniel.