We approximate from below an integrand L(t,u,v) by means of functions which enjoy Lipschitz properties with respect to u and v. Convexity on v is preserved.
An Approximation Result for Integrands of the Calculus of Variations / Gavioli, Andrea. - In: ATTI DEL SEMINARIO MATEMATICO E FISICO DELL'UNIVERSITA' DI MODENA. - ISSN 0041-8986. - STAMPA. - 30:(1981), pp. 243-253.