On Continuity and Decomposition of Positive Definite Functions
✍ Scribed by Zoltán Sasvári
- Publisher
- John Wiley and Sons
- Year
- 1989
- Tongue
- English
- Weight
- 329 KB
- Volume
- 140
- Category
- Article
- ISSN
- 0025-584X
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✦ Synopsis
Let G be a locally compact commutative group and let g and h be positive definite functions on G, which are not identically zero. We show that continuity of gh implies the existence of a character y of Gd (the discrete version of G) such that yg and y h are continuous. As corollary we get a special case of a result of K. DE LEEW and I. GLICKSBERO concerning almost continuous group representations. In the second part of the paper we prove decomposition theorems for positive definite functions defined on a neighbourhood of the zero.
📜 SIMILAR VOLUMES
Let f be a positive definite function on a locally compact abelian group G. In [3] we showed that measurability of 1 on an open neighbourhood of the zero implies measurability of f on G. As a main tool we used a result about the support of f [3, Th. I]. The aim of this note is to simplify the proof
Let \ be a nonnegative homogeneous function on R n . General structure of the set of numerical pairs ($, \*), for which the function (1&\ \* (x)) $ + is positive definite on R n is investigated; a criterion for positive definiteness of this function is given in terms of completely monotonic function