English

On the order structure of representable functionals

Functional Analysis 2016-08-15 v1 Operator Algebras

Abstract

The main purpose of this paper is to investigate some natural problems regarding the order structure of representable functionals on ^*-algebras. We describe the extreme points of order intervals, and give a nontrivial sufficient condition to decide whether or not the infimum of two representable functionals exists. To this aim we offer a suitable approach to the Lebesgue decomposition theory, which is in complete analogy with the one developed by Ando in the context of positive operators. This tight analogy allows to invoke Ando's results to characterize uniqueness of the decomposition, and solve the infimum problem over certain operator algebras.

Keywords

Cite

@article{arxiv.1608.03733,
  title  = {On the order structure of representable functionals},
  author = {Zsigmond Tarcsay and Tamás Titkos},
  journal= {arXiv preprint arXiv:1608.03733},
  year   = {2016}
}

Comments

20 pages

R2 v1 2026-06-22T15:18:22.374Z