On regular $^*$-algebras of bounded linear operators: A new approach towards a theory of noncommutative Boolean algebras

TL;DR

This paper introduces R*-algebras, a class of regular *-subalgebras of bounded operators, establishing their connection to Boolean algebras and exploring their properties and applications in noncommutative Boolean algebra theory.

Contribution

It defines R*-algebras, links them to Boolean algebras, and explores their properties, providing a new framework for noncommutative Boolean algebra research.

Findings

Unital commutative R*-algebras correspond to Boolean algebras

R*-algebras relate to AF C*-algebras and incomplete inner product spaces

Various theorems are applied to derive properties of R*-algebras

Abstract

We study (von Neumann) regular $^*$-subalgebras of $B(H)$, which we call R$^*$-algebras. The class of R$^*$-algebras coincides with that of "E$^*$-algebras that are pre-C$^*$-algebras" in the sense of Z. Sz\H{u}cs and B. Tak\'acs. We give examples, properties and questions of R$^*$-algebras. We observe that the class of unital commutative R$^*$-algebras has a canonical one-to-one correspondence with the class of Boolean algebras. This motivates the study of R$^*$-algebras as that of noncommutative Boolean algebras. We explain that seemingly unrelated topics of functional analysis, like AF C$^*$-algebras and incomplete inner product spaces, naturally arise in the investigation of R$^*$-algebras. We obtain a number of interesting results on R$^*$-algebras by applying various famous theorems in the literature.