Abstract
We review Fock space based quantum probability and in particular, the theory of stop times based on it. In the Fock space , a stop time may be defined as a positive self-adjoint operator
whose spectral resolution
is adapted to the natural filtration based on the splittings
Notes
All Hilbert spaces are complex; inner products are linear in the second entry.
In this paper, we do not consider stop times which can take the value ∞.
The three possibilities are known, at least to quantum probabilists who are also violinists, as left, right and double stopping.