N. Caroff et H. Frankowska, CONJUGATE-POINTS AND SHOCKS IN NONLINEAR OPTIMAL-CONTROL, Transactions of the American Mathematical Society, 348(8), 1996, pp. 3133-3153
We investigate characteristics of the Hamilton-Jacobi-Bellman equation
arising in nonlinear optimal control and their relationship with weak
and strong local minima. This leads to an extension of the Jacobi con
jugate points theory to the Bolza control problem. Necessary and suffi
cient optimality conditions for weak and strong local minima are state
d in terms of the existence of a solution to a corresponding matrix Ri
ccati differential equation.