Mathematical Proceedings of the Cambridge Philosophical Society

Research Article

Stopping non-commutative processes

Chris Barnetta1 and Terry Lyonsa1

a1 Department of Mathematics, Imperial College, London SW7

Stopping times are a powerful tool in the theory of stochastic processes, so it is natural to ask whether they have a counterpart in the theory of non-commutative processes. This paper is a part answer to that question. We show that the ‘formalism’ of stopping times carries over to a non-commutative context and prove an Optional Stopping Theorem.

(Received November 28 1984)

(Revised April 26 1985)