Self-adjoint extensions of differential operators and exterior topological derivatives in shape optimization

Self-adjoint extensions are constructed for a family of boundary value problems in domains with a thin ligament and an asymptotic analysis of a Lq-continuous functional is performed. The results can be used in numerical methods of shape and topology optimization of integral functionals for elliptic equations. At some stage of optimization process the singular perturbation of geometrical domain by an addition of thin ligament can be replaced by its approximation denned for the appropriate self-adjoint extension of the elliptic operator. In this way the topology variation of current geometrical domain can be determined and used e.g., in the level-set type methods of shape optimization.