We illustrate a novel characterization of nonequivalent statistical mechanical ensembles using the mean-field Blume–Emery–Griffiths (BEG) model as a test model. The novel characterization takes effect at the level of the microcanonical and canonical equilibrium distributions of states. For...

Microcanonical equations for some of the most usual thermodynamic properties of a system, suitable for molecular dynamics simulations, are derived from the Tsallis entropy functional using both the usual definition of temperature as a derivative of entropy and a modified physical one introduced...

The problem to express a natural number N as a product of natural numbers without regard to order corresponds to a thermally isolated non-interacting Bose gas in a one-dimensional potential with logarithmic energy eigenvalues. This correspondence is used for characterising the probability...

This short paper presents a nontechnical introduction to the problem of nonequivalent microcanonical and canonical ensembles. Both the thermodynamic and the macrostate levels of definition of nonequivalent ensembles are introduced. The many relationships that exist between these two levels are...

The one-particle distribution for the modulus of the velocity of a hard-disk fluid inside a small circular cavity is studied. Due to the geometry of the cavity, the total angular momentum L is conserved if the (elastic) particle–wall collisions are specular, leading to a new, special...

It is shown that a recent proposal to give physically meaningful definitions of temperature and pressure within Tsallis formalism for non-extensive thermostatistics leads to expressions which coincide with those obtained by using the standard Boltzmann formalism of statistical mechanics.

We study the mean-field φ4 model in an external magnetic field in the microcanonical ensemble using two different methods. The first one is based on Rugh's microcanonical formalism and leads to express macroscopic observables, such as temperature, specific heat, magnetization and...

A simple approximate expression is proposed for the energy dependence of the microcanonical density of states of a classical hard-particle fluid column of infinite height in a uniform gravitational field. This expression is based on the exact result in one dimension and depends on an effective...

The general formulas of the network for the power exponents of the degree distribution and the entropy are presented based on an open Liouville equation for the driven network. The proposed harmonious unifying hybrid preferential models (HUHPM) have been studied using the obtained formalism, in...

Travelling wave solutions for the Boussinesq-double sine-Gordon (B-sine-Gordon) equation, the Boussinesq-double sinh-Gordon equation (B-sinh-Gordon), and the Boussinesq-Liouville (BL) equation are formally derived. The approach rests mainly on the variable separated ODE method. Distinct sets of...