ABSTRACT

Conditioning as a functional analysis concept has applications not

only in probability but also in many other contexts in modern analysis.

In this chapter some of these ideas are discussed showing in particu-

lar that they are well-suited as (subMarkov) kernels in extending the

classical potential theory, analyzing bistochastic operators as well as

Reynolds operators arising in turbulence theory, and elsewhere. Also

it is shown how conditional expectation operators can be used as mod-

els for describing general (contractive) projections in many function

spaces. Almost all these applications are based on regular conditional

measures, and the theory is then executed from the “idealistic” view.

10.1 Introduction and motivation