Classification of static field effects in smectic A mesophase

Bifurcational analysis of the extended Landau-de Gennes model of smectic A (A) liquid crystal in external field is performed. Topological classificati on of phase diagrams of the system in "field-temperature'' coordinates is m ade. Depending on mesogeneous properties the following static field effects are demonstrated to realize: a) suppression of the nematic (N)-paranematic (pN) phase transition in the critical end point (CEP) (the Wojtowich-Sheng effect); b) induction of an intermediate nematic phase (the Rosenblatt eff ect) followed by its suppression (the induced Wojtowich-Sheng effect); c) i nduction of tricritical point (TCP) on the A-N phase transition line (the R osenblatt-Hama effect); d) induction of the A-nonspontaneous nematic (NSN T CP in combination with the induced Wojtowich-Sheng effect; e) induction of the A-pN TCP in combination with the induced Wojtowich-Sheng effect (the Le lidis-Durand effect); f) induction of the A-NSN-pN triple point (TP) by an arbitrary weak field; g) coincidence of the A-NSN-pN TP and the A-NSN TCP u nder the influence of the field (field analogue of the Achard-Sigaud-Hardou in effect); h) realization of the A-pN TCP in combination with prohibition of the induced Wojtowich-Sheng effect. Conditions are formulated leading to realization and prohibition of effects listed above.