S. Lenhart et V. Protopopescu, OPTIMAL-CONTROL FOR PARABOLIC-SYSTEMS WITH COMPETITIVE INTERACTIONS, Mathematical methods in the applied sciences, 17(7), 1994, pp. 509-524
We consider a two-dimensional parabolic system with general competitiv
e interactions as a two-player game with conflicting objectives and wi
th controls on the inhomogeneous (source) terms. We show the existence
of an optimal solution of the game as the saddle point of a suitable
objective functional.