measurability of stochastic processes
For a continuous-time stochastic process adapted to a given filtration (http://planetmath.org/FiltrationOfSigmaAlgebras) on a measurable space , there are various conditions which can be placed either on its sample paths or on its measurability when considered as a function from to . The following theorem lists the dependencies between these properties.
Theorem.
Let be a real valued stochastic process.Then, is optional if it is adapted and right-continuous, it is predictable if it is adapted and left-continuous. Furthermore, each of the following properties implies the next.
- 1.
is predictable.
- 2.
is optional.
- 3.
is progressive.
- 4.
is adapted and jointly measurable.