The dynamics of the approach to equilibrium of the hydrogen atom is investigated numerically through a Monte Carlo procedure. We show that, before approaching ionization, the hydrogen atom may live in a quasi-equilibrium state, characterized by aging, whose duration increases exponentially as...

We discuss a property of our recently introduced generalized canonical ensemble [M. Costeniuc, R.S. Ellis, H. Touchette, B. Turkington, The generalized canonical ensemble and its universal equivalence with the microcanonical ensemble, J. Stat. Phys. 119 (2005) 1283]. We show that this ensemble...

A special quantum-group oscillator presents an upper bound in its energy spectrum, which is preceded by an accumulation of infinite levels. The standard Boltzmann–Gibbs (BG) statistical-mechanics formalism is inadequate for dealing with such systems, since the partition function diverges for...

The pinning effect induced by two different types of spatial inhomogeneities on the dynamics and equilibria of a one-spike solution to the one-dimensional Gierer–Meinhardt (GM) activator–inhibitor model of morphogenesis is studied. The first problem that is treated is the shadow problem that...

We discuss the phase behaviour of spherical hard-core particles, with an attractive potential, as described by a hard-core Yukawa model. The ratio of the range of the attraction to the diameter of the particles is an important control parameter of the problem. Upon decreasing the range of the...

We show that a stochastic process on a complex plane can simulate decay from a metastable state. The simplest application of the method to a model in which the approach to equilibrium occurs through transitions over a potential barrier is discussed. The results are compared with direct numerical...