English

A reduction method for noncommutative $L_p$-spaces and applications

Operator Algebras 2009-09-01 v2 Functional Analysis

Abstract

We consider the reduction of problems on general noncommutative LpL_p-spaces to the corresponding ones on those associated with finite von Neumann algebras. The main tool is a unpublished result of the first named author which approximates any noncommutative LpL_p-space by tracial ones. We show that under some natural conditions a map between two von Neumann algebras extends to their crossed products by a locally compact abelian group or to their noncommutative LpL_p-spaces. We present applications of these results to the theory of noncommutative martingale inequalities by reducing most recent general noncommutative martingale/ergodic inequalities to those in the tracial case.

Keywords

Cite

@article{arxiv.0806.3635,
  title  = {A reduction method for noncommutative $L_p$-spaces and applications},
  author = {Uffe Haagerup and Marius Junge and Quanhua Xu},
  journal= {arXiv preprint arXiv:0806.3635},
  year   = {2009}
}
R2 v1 2026-06-21T10:53:20.404Z