Zero-sum Dynkin games under common and independent Poisson constraints

Abstract: Zero-sum Dynkin games under the Poisson constraint have been studied widely in the recent literature. In such a game the players are only allowed to stop at the event times of a Poisson process. The constraint can be modelled in two different ways: either both players share the same Poisson process (the common constraint) or each player has her own Poisson process (the independent constraint). In the Markovian case where the payoff is given by a pair of functions of an underlying diffusion, we give sufficient conditions under which the solution of the game (the value function, and the optimal stopping sets for each player) under the common (respectively, independent) constraint is also the solution of the game under the independent (respectively, common) constraint. Roughly speaking, if the stopping sets of the maximiser and minimiser in the game under the common constraint are disjoint, then the solution to the game is the same under both the common and the independent constraint. However, the fact that the stopping sets are disjoint in the game under the independent constraint, is not sufficient to guarantee that the solution of the game under the independent constraint is also the solution under the common constraint.