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Strictly Positive Definite Functions

✍ Scribed by Kuei-Fang Chang


Publisher
Elsevier Science
Year
1996
Tongue
English
Weight
490 KB
Volume
87
Category
Article
ISSN
0021-9045

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✦ Synopsis


We give a complete characterization of the strictly positive definite functions on the real line. By Bochner's theorem, this is equivalent to proving that if the separated sequence of real numbers [a n ] describes the points of discontinuity of a distribution function, there exists an almost periodic polynomial with the zeros [a n ]. We prove a useful necessary condition that every strictly normalized, positive definite function f satisfies | f (x)| <1 for all x{0. It is a sufficient condition for strictly positive definiteness that if the carrier of a nonzero finite Borel measure on R is not a discrete set, then the Fourier Stieltjes transform +^of + is strictly positive definite.


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