Nonlinear hydrodynamics of strongly deformed smectic C and C* liquid crystals

The statics and dynamics of smectic C (and C*) liquid crystals has been a long-standing topic for investigations. All the previous descriptions, however, have been restricted in some sense. Either the theories were linear, or flat layers were assumed, or the layer thickness was taken to be constant, or only statics was considered, or the description (in the chiral case) included terms not compatible with layering. Here we will give a nonlinear hydrodynamic theory, which applies to strongly curved layers, non-flat ‘ground’ states, strongly compressed layers as well as strongly deformed director orientations. Some discrepancies between previous theories are resolved.