×

Partial observation control in an anticipating environment. (English. Russian original) Zbl 1055.93075

Russ. Math. Surv. 59, No. 2, 355-375 (2004); translation from Usp. Mat. Nauk 59, No. 2, 161-184 (2004).
Summary: A study is made of a controlled stochastic system whose state \(X(t)\) at time \(t\) is described by a stochastic differential equation driven by Lévy processes with filtration \(\{{\mathcal F}_t\}_{t\in [0,T]}\). The system is assumed to be anticipating, in the sense that the coefficients are assumed to be adapted to a filtration \(\{{\mathcal G}_t\}_{t\geq 0}\) with \({\mathcal F}_t\subset{\mathcal G}_t\) for all \(t\in [0,T]\). The corresponding anticipating stochastic differential equation is interpreted in the sense of forward integrals, which naturally generalize semimartingale integrals. The admissible controls are assumed to be adapted to a filtration \(\{{\mathcal E}_t\}_{t\in [0,T]}\) such that \({\mathcal E}_t\subset{\mathcal F}_t\) for all \(t\in [0,T]\). The general problem is to maximize a given performance functional of this system over all admissible controls. This is a partial observation stochastic control problem in an anticipating environment. Examples of applications include stochastic volatity models in finance, insider influenced financial markets, and stochastic control of systems with delayed noise effects. Some particular cases in finance, involving optimal portfolios with logarithmic utility, are solved explicitly.

MSC:

93E20 Optimal stochastic control
60H07 Stochastic calculus of variations and the Malliavin calculus
91G80 Financial applications of other theories