Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-25T14:33:44.107Z Has data issue: false hasContentIssue false

Random Fourier–Stieltjes transforms on partially ordered ǵroups

Published online by Cambridge University Press:  24 October 2008

John Fournier
Affiliation:
University of British Columbia

Extract

If one changes at random the signs of the Fourier coefficients of an L2 function the result is still the sequence of Fourier coefficients of an L2 function. L2 is the only LP space with this property; in fact if a sequence remains a Fourier transform for every insertion of ± signs then it is really the transform of an L2 function ((6), p. 215, Theorem 8·14). Our main theorem is a version of this principle, for sequences defined on suitable subsets of a group; it is phrased in terms of large sets of choices of ± signs rather than all sequences of ± signs.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1970

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

(1)Fine, N.On the Walsh functions. Trans. Amer. Math. Soc. 65 (1949), 372414.CrossRefGoogle Scholar
(2)Fournier, J.Extensions of a Fourier multiplier theorem of Paley. Pacific J. Math. 30 (1969).CrossRefGoogle Scholar
(3)Gaudry, G. I.Changes of signs of restrictions of Fourier–Stieltjes transforms. Proc. Cambridge Philos. Soc. 66 (1969), 295300.CrossRefGoogle Scholar
(4)Kahane, J.-P., Séries de Fourier Aléatoires, 2nd ed., Les Presses de l'Université de Montreal (Montreal, 1966).Google Scholar
(5)Rudin, W.Fourier analysis on groups (Interscience; New York, 1962).Google Scholar
(6)Zygmund, A.Trigonometric series, 2nd ed., vol. I. Cambridge University Press (Cambridge, 1959).Google Scholar