Raf Dekeyser

Critical Ising lines of the d=2 Ashkin-Teller model

The universal critical point ratio

Series expansions for a generalized XY hamiltonian

Q

A convergent expression for the partition function of a partially ionized hydrogen plasma

is exploited to determine positions of the critical Ising transition lines on the phase diagram of the Ashkin-Teller (AT) model on the square lattice. A leading-order expansion of the ratio

Higher-order correlations in the two-dimensional ising model

Q

The dielectric constant in the Hartree-Fock approximation

in the presence of a non-vanishing thermal field is found from finite-size scaling and the corresponding expression is fitted to the accurate perturbative transfer-matrix data calculations for the

Differential renormalization of van der Waals spin models

L\times L

Effective field methods with correlations in magnetic systems

square clusters with

Comment on ‘‘Behavior of polymer end‐to‐end distance in two dimensions at the theta point’’

L\leq 9

Influence of the reaction field on the nature of the phase transition in the Potts model

.

Series expansions for a generalized XY hamiltonian: II. Tricritical behaviour of the Takagi model

Series expansions are derived for the free energy and the fluctuations of a generalized hamiltonian. These series are analysed in the special case of the XY hamiltonian on an f.c.c. lattice in an external parallel magnetic field. The critical indices seem to be independent of the field.