Tangential Flows in Fluid Membranes and their Effect on the Softening of Curvature Rigidity with Scale

Abstract

During perpendicular displacements of fluid membranes, lipids must flow along the membrane to conserve lipid density. The kinetic energy of this flow must be taken into account when setting up the canonical phase space needed in the thermal statistics of fluid membranes. We confirm an earlier calculation of Helfrich on the precise amount of softening of curvature rigidity of fluid membranes as a function of distance scale.