Handling the low-frequency breakdown of the PMCHWT integral equation with the quasi-Helmholtz projectors

This contribution presents a quasi-Helmholtz projectors based regularization of the low frequency breakdown of the PMCHWT integral equation. The PMCHWT equation in the low-frequency regime shows an ill-conditioned behavior inherited from the Electric Field Integral Operators it contains. The stabilization via quasi-Helmholtz projectors, differently from the use of standard Loop-Star/Tree decompositions, does not introduce an additional mesh-size-related ill-conditioning and it applies smoothly to both simply and non-simply connected geometries. The presentation of the main formulation will be complemented by numerical results demonstrating the effectiveness and accuracy of the proposed scheme.