Uniform Bounds on the Gradients in Composite Media Containing Close-to-Touching Inclusions: An integral Equation Approach
Résumé
We discuss point wise bounds on the gradient of the solution to a scalar elliptic PDE in a 2D composite media containing smooth inclusions as the inter-inclusion distance tends to 0. THe solution is expressed in terms of layer potentials and we study the uniform invertibility of the associated system. We also show that, when the inclusions are disks, the spectrum of the Neumann-Poincaré operator appearing in the integral equations relates to the bounds on the gradients.