CRITICAL-DYNAMICS IN THE PEARLING INSTABILITY OF MEMBRANES

We report quantitative measurements above threshold in the pearling in stability of cylindrical membranes. Induced by optical tweezers, the i nstability propagates outward from the laser trap with well defined wa velength, and velocity. All measured quantities scale with the reduced tension control parameter epsilon = (Sigma - Sigma(c))/Sigma(c). A cr itical slowing down for initiation of the instability is observed. The values of the velocity, wavelength, and delay time agree with margina l stability and linear analysis. Measurements very close to threshold are strongly masked by thermal fluctuations.