The p-version of the boundary element method for weakly singular
operators on piecewise plane open surfaces
Alexei Bespalov and Norbert Heuer
Numer. Math. 106 (1), 69-97, 2007.
We study piecewise polynomial approximations in negative order Sobolev norms of
singularities which are inherent to Neumann data of elliptic problems of second order
in polyhedral domains. The worst case of exterior crack problems in three
dimensions is included. As an application, we prove an optimal a priori error
estimate for the p-version of the BEM with weakly singular operators on
polyhedral surfaces and piecewise plane open screens.