Convective and absolute instabilities in viscoelastic fluid convection

Convection in viscoelastic fluids may be induced by oscillatory or stationa ry instabilities. When the oscillatory instability appears first, the syste m may be described, in its vicinity by coupled Ginzburg-Landau equations. W e study the convective and absolute instabilities of the steady states of t hese equations. We analyze pattern selection and stability in deterministic and stochastic systems and discuss the possibility of noise-induced phase transitions. (C) 1999 Elsevier Science B.V. All rights reserved.