Search arXivSearch

arXiv · math/0612015

Positive forms on Banach spaces

Abstract

The first representation theorem establishes a correspondence between positive, self-adjoint operators and closed, positive forms on Hilbert spaces. The aim of this paper is to show that some of the results remain true if the underlying space is a reflexive Banach space. In particular, the construction of the Friedrichs extension and the form sum of positive operators can be carried over to this case.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Balint Farkas, Mate Matolcsi. 2006-12-01. Positive forms on Banach spaces. https://arxiv.org/abs/math/0612015

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Proper splittings of Hermitian operators

In this article we deepen the study of proper splittings of Hilbert space operators, with special emphasis on proper splittings of Hermitian operators. On the one hand, we improve characterizations given in [Fongi $\&$ Gonzalez, J. Math. Anal. Appl., 545 (2025) 129093] of the convergence of both the polar proper and the Moore Penrose proper splittings. On the other hand, we introduce new proper splittings and we compare their convergence with those of the polar and the Moore Penrose proper splittings.

math.FA

Localized frames without inequalities

We consider countable families of vectors in a separable Hilbert space, which are mutually localized with respect to a fixed localized Riesz basis. We prove the equivalence of the frame property and nine conditions that do not involve any inequalities. This is done by studying the properties of their frame-related operators on the co-orbit spaces generated by the reference Riesz basis. We apply our main result to the setting of shift-invariant spaces and obtain new conditions for stable sets of sampling.

math.FA