YOUNG MEASURE APPROACH TO CHARACTERIZATION OF BEHAVIOR OF INTEGRAL FUNCTIONALS ON WEAKLY CONVERGENT SEQUENCES BY MEANS OF THEIR INTEGRANDS

It is known that sequential weak lower semicontinuity and weak-strong convergence (in the scalar case) properties of integral functionals ma y be characterized by means of their integrands. In this paper we intr oduce a Young measure approach obtaining both these results and the ch aracterization for the second property in the vector-valued case. We d iscuss also motivations for the definition of strict quasiconvexity, a nd point out that the characterization of the classes of functionals h aving weak-strong convergence property everywhere is not a trivial pro blem in the general case. (C) Elsevier, Paris.