The aim of this paper is to unify and extend some of the various results on the ordering of option prices in exponential semimartingale models. This is a problem of interest not only for financial applications but similar questions also arise in the ordering properties of Markovian networks or in the problem to develop consistency results for risk measures for portfolio vectors with respect to ...

It is possible to construct (cf [1] and [2]) a positive process (Yψ,t) indexed by Bernstein functions and time which, for fixed t, is Markovian with respect to the composition of Bernstein functions, and for fixed ψ, is the subordinator associated with the Bernstein function ψ. In the same manner a realization (XYψ,t) can be obtained of all the subordinated processes of a Markov process (Xt). T...

in this paper, we determine the structure of the space of multipliers of the range of a composition operator cφ that induces by the conditional expectation between two lp() spaces.