Complex systems and Biological physics seminar [before December 2013]

Temperature of small systems: a well defined quantity

by Prof. Angelo Vulpiani (Dipartimento di Fisica, Universita' Sapienza)

Europe/Stockholm
122:026

122:026

Description
In equilibrium thermodynamics there is a one-to-one relation between the energy of a (macroscopic) systems and its temperature. On the other hand there is a long debated topic (which includes Kittel and Mandelbrot) on the "temperature fluctuation", in particular for small systems. We discuss how, following an approach based on the mathematical statistics, it is possible to define, in a non ambiguous way, the temperature even in small systems which are in contact with a reservoir. From the analysis of a specific model of thermometer one understands how the uncertainty on the temperature is due to the typical time of the underlying dynamics, while the limited number of degrees of freedom is not relevant. Work in collaboration with M. Falcioni, A. Puglisi, A. Sarracino & D. Villamaina