Banach Journal of Mathematical Analysis

Radon–Nikodym theorems for operator-valued measures and continuous generalized frames

Abstract

In this article we determine that an operator-valued measure (OVM) for Banach spaces is actually a weak∗ measure, and then we show that an OVM can be represented as an operator-valued function if and only if it has $\sigma$-finite variation. By the means of direct integrals of Hilbert spaces, we introduce and investigate continuous generalized frames (continuous operator-valued frames, or simply CG frames) for general Hilbert spaces. It is shown that there exists an intrinsic connection between CG frames and positive OVMs. As a byproduct, we show that a Riesz-type CG frame does not exist unless the associated measure space is purely atomic. Also, a dilation theorem for dual pairs of CG frames is given.

Article information

Source
Banach J. Math. Anal., Volume 11, Number 2 (2017), 363-381.

Dates
Received: 1 March 2016
Accepted: 9 June 2016
First available in Project Euclid: 22 February 2017

Permanent link to this document
https://projecteuclid.org/euclid.bjma/1487732419

Digital Object Identifier
doi:10.1215/17358787-0000008X

Mathematical Reviews number (MathSciNet)
MR3612170

Zentralblatt MATH identifier
1383.43003

Citation

Li, Fengjie; Li, Pengtong. Radon–Nikodym theorems for operator-valued measures and continuous generalized frames. Banach J. Math. Anal. 11 (2017), no. 2, 363--381. doi:10.1215/17358787-0000008X. https://projecteuclid.org/euclid.bjma/1487732419

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