Johal, Ramandeep S.Planes Vila, AntoniVives i Santa-Eulàlia, Eduard2011-07-072011-07-0720031539-3755https://hdl.handle.net/2445/18741The extended Gaussian ensemble (EGE) is introduced as a generalization of the canonical ensemble. This ensemble is a further extension of the Gaussian ensemble introduced by Hetherington [J. Low Temp. Phys. 66, 145 (1987)]. The statistical mechanical formalism is derived both from the analysis of the system attached to a finite reservoir and from the maximum statistical entropy principle. The probability of each microstate depends on two parameters ß and ¿ which allow one to fix, independently, the mean energy of the system and the energy fluctuations, respectively. We establish the Legendre transform structure for the generalized thermodynamic potential and propose a stability criterion. We also compare the EGE probability distribution with the q-exponential distribution. As an example, an application to a system with few independent spins is presented.8 p.application/pdfeng(c) The American Physical Society, 2003Física estadísticaTermodinàmicaSistemes dinàmics diferenciablesStatistical physicsThermodynamicsDifferentiable dynamical systemsinfo:eu-repo/semantics/article513167info:eu-repo/semantics/openAccess