“…Even if numerous works exist on the calculus of shape derivatives of various shape functionals [11][12][13]15,34], in the framework of boundary integral equations the scientific literature is not extensive. However, one can cite the papers [29,31,30], where Potthast has considered the question, starting with his PhD thesis [32], for the Helmholtz equation with Dirichlet or Neumann boundary conditions and the perfect conductor problem, in spaces of continuous and Hölder continuous functions.…”