We obtain the relations between macroscopic thermodynamical properties and microscopic ensemble averages of a system in contact with a heat bath which has a finite number of degrees of freedom. Our approach is based on the geometry of the accessible phase space of the system. By using a suitable...

We have recently shown that the dispersion and the energy square relative fluctuations of a finite system in contact with a finite heat bath depends on the number of degrees of freedom of the system and of the bath. In this paper, we present numerical simulations which support this result.