Figure 3

Membrane shape for spherical swimmers.

(a) Asphericity parameter for N_b = 50 (blue symbols), N_b = 100 (red symbols) and N_b = 150 (green symbols), the lines are a guide to the eye. The membrane approaches a circular shape with increasing ϕ. (b) The red circles are (R_g − R₀)/R_g (the red line is a guide to the eye), the black symbols represent PN_b/2πk and the green line is the fit to Eq. (15). The data are plotted as a function of the area fraction computed with respect the circle of radius R_g for N_b = 150. Inset: the quantity c/(1−c) as a function of N_b. (c) Probability distributions of the local curvatures for N_b = 100 for increasing ϕ from 0.05 (blue) to 0.80 (red). (d) Parameter β as a function of ϕ for N_b = 50, 100, 150 (blue, red and green), the black dashed line is β for a Gaussian distribution. The grey area represents the estimated ϕ_c range. Inset: ϕ_c obtained from the decoupling between pressure and deformation (blue symbols) the line is the estimate of ϕ_c given by ϕ (N_b = N_s).