A Curie-Weiss Theory of the Continuum Widom-Rowlinson Model

A version of the continuum Widom-Rowlinson model is introduced and studied. It is a two-component gas of point particles placed in ${\mathbf{R}}^d$ in which like particles do not interact and unlike particles contained in a given vessel of volume $V$ repel each other with intensity $a\mathrm{/}V$. This model is thermodynamically equivalent to a one-component gas with multi-particle interaction. For both models, a rigorous theory of a phase transition is presented and the ways of its construction in the framework of the grand canonical formalism are outlined.