© 2000 by Oxford University Press
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Rawlin's method and the diaphonous cone
( Department of Mathematics, The University, Dundee DD1 4HN, UK )
Approximate expansions are obtained for the field when an electromagnetic wave is scattered by a dielectric circular cone with refractive index near unity. They indicate that the field near the tip of the cone contains not only powers of the distance but also its logarithm.
The analysis entails the singular behaviour of an integral of a product of Hankel functions as a generalized function. Also a uniformly valid asymptotic formula for the hypergeometric function with parameters outside the usual range is derived.