Agrachev, A. A.; Sarychev, A. V. On abnormal extremals for Lagrange variational problems. (English) Zbl 0826.49012 J. Math. Syst. Estim. Control 5, No. 1, 127-130 (1995). Summary: Abnormal extremals for the problem of relative extremum and the Lagrange problem of the calculus of variations are studied. Legendre-Jacobi-type necessary/sufficient minimality conditions for abnormal extremum are derived and Morse-type index and nullity theorems for abnormal extremals of the Lagrange problem are established.[Full electronic manuscript (published January 1, 1995) = 32 pp, 350,492 bytes. Retrieval Code: 99949]. Cited in 18 Documents MSC: 49K15 Optimality conditions for problems involving ordinary differential equations 90C30 Nonlinear programming 93B05 Controllability 93B29 Differential-geometric methods in systems theory (MSC2000) Keywords:abnormal extremals; index theorems; Lagrange problem; minimality conditions; nullity theorems PDF BibTeX XML Cite \textit{A. A. Agrachev} and \textit{A. V. Sarychev}, J. Math. Syst. Estim. Control 5, No. 1, 127--130 (1995; Zbl 0826.49012) OpenURL