𝔖 Bobbio Scriptorium
✦   LIBER   ✦

On Positive Definiteness of Some Functions

✍ Scribed by Victor P Zastavnyi


Publisher
Elsevier Science
Year
2000
Tongue
English
Weight
271 KB
Volume
73
Category
Article
ISSN
0047-259X

No coin nor oath required. For personal study only.

✦ Synopsis


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 functions; a connection of this problem with the Schoenberg problem on positive definiteness of the function exp(&\ * (x)) is found. We also obtain a general sufficient condition of Polya type for a function f ( (x)) to be positive definite on R n .


πŸ“œ SIMILAR VOLUMES


Strictly Positive Definite Functions
✍ Kuei-Fang Chang πŸ“‚ Article πŸ“… 1996 πŸ› Elsevier Science 🌐 English βš– 490 KB

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 periodi

On Continuity and Decomposition of Posit
✍ ZoltΓ‘n SasvΓ‘ri πŸ“‚ Article πŸ“… 1989 πŸ› John Wiley and Sons 🌐 English βš– 329 KB

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

Addendum to the Paper β€žOn the Measurabil
✍ ZoltΓ‘n SasvΓ‘ri πŸ“‚ Article πŸ“… 1987 πŸ› John Wiley and Sons 🌐 English βš– 116 KB πŸ‘ 1 views

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