Measures on product spaces and the existence of strong Baire liftings

Abstract

Some notions are introduced for studying measures on product spaces, the main concept being that of property (*). In case when the topological factors are separable metric spaces, this property is equivalent to the completion regularity. We prove that (*) is preserved under arbitrary products of measure spaces. As a consequence, we deduce a series of related results in measure theory (some of which are known). In particular, the following extension of a result by Losert is obtained: Subject to CH, every product of ⩽ℵ2 many completion regular measures, each supported on any product of ⩽ℵ1 many compact metric spaces admits a strong Baire lifting.