  In linear elastic theory, membrane deformation energy caused by inclusions
(e.g., membrane-spanning peptides in lipid bilayers) can be rigorously
presented in terms of coupled harmonic oscillators. The general expressions for
the corresponding "effective spring constants" are derived here for quite
general boundary conditions allowing, e.g., for the azimuthal variation of the
contact slope. The case of two insertions is considered in more details.
