Singular normal extremals and conjugate points for Bolza functionals
In this paper the author obtains an extremization condition for the most general form of Bolza type functions with constraints on the final state. These results are available also for Lagrange functionals with fixed endpoints. The author uses the class of adjoint variations to express the second variation as well as the nonnegativity condition for the singular control. He obtains the minimum value of the second variation for state variations that do not admit conjugate points with respect to the initial and final time.
scientific article; zbMATH DE number 1930213