ON THE EXISTENCE OF INFINITELY MANY CRITICAL POINTS OF THE EVEN FUNCTIONAL integral from n=Ω to (F(x, u, Du)dx) IN W_0~(1,p)

§1. Introduction In the paper [1], Pacella and Tricarico proved that the existence of infinitely many critical points of even functional integral from Ω to (F(x,u,Du)dx) in space W_0~(1,2). As far as our knowledge goes, the paper [1] is the first investigation of general functional integral from Ω to (F(x,u,Du)dx) in Hilbert space W_0~(1,2), but the techniques used in the paper[1], was restricted to Hilbert space. In the same year as when [1] had published, we independently proved [2] the