Frank-Olme Speck
(Instituto Superior Técnico, UTL and CEAF)
" Diffraction from a
three-quarter-plane using an abstract Babinet principle "
Abstract. The
modelling of diffraction of time-harmonic electromagnetic or acoustic
waves from obstacles and screens leads to boundary value problems for
the three-dimensional Helmholtz equation with Dirichlet, Neumann or
other conditions on the boundary. A prominent example is the problem of
diffraction from a quarter-plane in R3, which admits an explicit
solution. In this paper the Dirichlet and Neumann problems for the
three-quarter-plane are solved by an algebraic trick: the matricial
coupling of operators associated to ”dual” boundary value problems, a
kind of abstract Babinet principle.
