English

Dilations for operator-valued quantum measures

Functional Analysis 2021-09-21 v1 Operator Algebras

Abstract

This paper concerns the dilations of Banach space operator-valued quantum measures. While the recently developed general dilation theory can lead to a projection (idempotent) valued dilation for any quantum measure over the projection lattice for a von Neumann algebra that dose not contain type I2I_{2} direct summand, such a dilation does not necessarily guarantee the preservation of countable additivity of the quantum measure. So it remain an open question whether every countably additive B(X)B(X)-valued quantum measure can be dilated to a countably additive projection-valued measure.The main purpose of this paper is to prove that such a dilation can be constructed if one of the following two conditions is satisfied: (i) the underling Banach space X=pX = \ell_{p} (1p<2(1\leq p < 2) or it has Schur property, (ii) the quantum measure has bounded pp-variation for some 1p< 1\leq p < \infty . All of these were achieved by establishing a non-commutative version of a minimal dilation theory on the so-called elementary dilation space equipping with an appropriate dilation norm. In particular, the newly introduced pp-variation norm on the elementary dilation space allows us to prove that every operator-valued quantum measure with bounded pp-variation has a projection-valued quantum measure dilation that preserves the boundedness of the pp-variation.

Keywords

Cite

@article{arxiv.2109.09042,
  title  = {Dilations for operator-valued quantum measures},
  author = {Deguang Han and Qianfeng Hu and David R. Larson and Rui Liu},
  journal= {arXiv preprint arXiv:2109.09042},
  year   = {2021}
}

Comments

28 pages

R2 v1 2026-06-24T06:06:30.427Z