2024/03/14 by M. D. Groves, Groves, Mark D., Dan J. Hill +1 · 1 citation
Mathematics · #Advanced Banach Space Theory #Advanced Harmonic Analysis Research #Approximation Theory and Sequence Spaces
paper · pdf · doi:10.48550/arxiv.2403.09372
This paper is concerned with complex Banach-space valued functions of the form fk(rcosθ,rsinθ,z)=ei k θfk(r,z), r ∈ [0,∞), θ∈ \mathbbT1, z ∈ ℝ, for some k ∈ ℤ. It is demonstrated how classical and Sobolev spaces for the radial function fk can be constructed in a natural fashion from the corresponding standard function spaces for fk. A theory of radial distributions is derived in the same spirit. Finally, a new class of Hankel spaces for the case fk=fk(r) is introduced. These spaces are the radial counterparts of the familiar Bessel-potential spaces for functions defined on ℝd. The paper concludes with an application of the theory to the Dirichlet boundary-value problem for Poisson's equation in a cylindrical domain.