In this paper, for any submartingale of class (Σ) defined on a filtered probability space (Ω,F,P,(Ft)t≥0) satisfying some technical conditions, we associate a σ-finite measure Q on (Ω,F), such that for all t≥0, and for all events Λt∈Ft: Q[Λt,g≤t]=EP[1ΛtXt], where g is the last...

In this paper, we consider the special class of positive local submartingales (Xt) of the form Xt=Nt+At, where the measure is carried by the set {t:Xt=0}. We show that many examples of stochastic processes studied in the literature are in this class and propose a unified approach based on...

In this survey on last passage times, we propose a new viewpoint which provides a unified approach to many different results which appear in the mathematical finance literature and in the theory of stochastic processes. In particular, we are able to improve the assumptions under which some...

This note deals with the question: what remains of the Burkholder-Davis-Gundy inequalities when stopping times T are replaced by arbitrary random times [rho]? We prove that these inequalities still hold when T is a pseudo-stopping time and never holds for ends of predictable sets.

Given a random time, we give some characterizations of the set of martingales for which the stopping theorems still hold. We also investigate how the stopping theorems are modified when we consider arbitrary random times. To this end, we introduce some families of martingales with remarkable...

In this paper we model the situation where a non-renewable investment is given, for instance a resource reservoir, and show how to optimally trade-off between dividends and leverage, in order to maximize a performance indicator for shareholders, up to the bankruptcy time. We then study the way...