NOVEL BIFURCATION SET CROSS-SECTION METHOD FOR TOPOLOGICAL ANALYSIS OF PHASE-DIAGRAMS

Bifurcation set cross-section method is proposed which allows to const ruct all the possible, at least, two-dimensional phase diagrams of mod els described by multiparametric thermodynamic potentials. The method is applied to investigation of the de Gennes model of smectic A mesoph ase in external field. Among other results, the most important one is that all the critical (end critical, tri-critical etc.) points of phas e diagrams are peculiar points of the corresponding bifurcation sets.