Energies and shapes of deformation. (a) Normalized free energy of a budding membrane as a function of normalized domain radius ρ relative to the flat radius ρd, in the constant membrane tension ensemble, for a few values of domain size ρd and normalized surface tension σ. The solid lines are the numerical results; the dashed lines correspond to the simplified analytical model. Sketches at ρ/ρd = 0, 0.5, and 1 show corresponding analytical shapes. (b) Meridional curves from axisymmetric finite element numerical minimization of free energy for σ = 0.25. The domain is in red, and the matrix is in blue. Clockwise from upper left: equilibrium deformed configurations for .