HOẠT ĐỘNG TRONG TUẦN

Second-order necessary conditions and sufficient conditions, with the envelope-like effect, for optimality in nonsmooth multiobjective mathematical programming are established. We use set-valued second-order directional derivatives and impose strict differentiability for necessary conditions and l-stability for sufficient conditions, avoiding continuous differentiability. The results improve and sharpen several recent existing ones. Examples are provided to show advantages of our theorems over some known ones in the literature.