Functional Analysis and Applications Seminar 

04/04/2003, 14:00 — 16:00 — Room P3.10, Mathematics Building
Frank-Olme Speck, Instituto Superior Técnico, U.T. Lisboa

On a Class of Wedge Diffraction Problems Posted by Erhard Meister

A class of canonical wedge diffraction problems was formulated by E. Meister in 1986 and subsequently treated by an operator theoretical approach in various publications of his research group. Certain subclasses of those problems, recognized of being unsolved, are subject of the present talk. Some of them are now successfully attacked by the help of

1. operator relations,
2. a new factorization approach for convolution type operators with symmetry, and
3. the method of minimal normalization in Sobolev spaces.

Several gaps of the existing theory are filled, new problems are recognized reflecting the challenges of the present state of the art. The talk is mainly based upon joint recent work with L. Castro and F. S. Teixeira.