Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-12-02T23:31:52.392Z Has data issue: false hasContentIssue false

Stone's theorem and completeness of orthogonal systems

Published online by Cambridge University Press:  09 April 2009

B. D. Craven
Affiliation:
University of Melbourne
Rights & Permissions [Opens in a new window]

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

It is well known (e.g. Stone [1]) that the Stone-Weierstrass approximation theorem can be used to prove the completeness of various systems of orthogonal polynomials, e.g. Chebyshev polynomials. In this paper, Stone's theorem is used to prove a more general completeness theorem, which includes as special cases Plancherel's theorem, the corresponding theorem for Hankel transforms, the completeness of various polynomial systems, and certain expansions in Jacobian elliptic functions. The essential feature common to all these systems is a certain algebraic structure — if S is an appropriate vector space spanned by orthogonal functions, then the algebra A generated by S is contained in the closure of S in a suitable norm.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 1971

References

[1]Stone, M. H., A generalized Weierstrass approximation theorem (Studies in Mathematics, Vol. 1, Math. Assoc. of America, 1962).Google Scholar
[2]Naimark, M. A., Normed Rings (Noordhoff, Groningen, 1964).Google Scholar
[3]Milne-Thomson, L. M., Jacobian Elliptic Function Tables (Dover, New York, 1950).Google Scholar
[4]Magnus, W. and Oberhettinger, F., Formulas and theorems for the functions of mathematical physics (Chelsea, New York, 1954).Google Scholar