Extensions of Representable Positive Linear Functionals to Unitized Quasi *-Algebras

Abstract

It is known that, under certain conditions, *-representability and extensibility to the unitized *-algebra of a positive linear functional, defined on a *-algebra without unit, are equivalent. In this paper, a new condition for an analogous result is given for the case of a hermitian linear functional defined on a quasi *-algebra $(\A,\Ao)$ without unit.