An Application of a Variational Theorem of Mixed Type to a Superlinear Elliptic Problem

We prove the existence of four solutions for the superlinear subcritical elliptic problemyDusluy uy. pyte1 in V, us0 on ­V, when t)0, lj-l -ljq1 and l is close enough to ljq1for jG1 here e1is the positive eigenfunction corresponding to l1 and li.iG1 is the sequence of the eigenvalues of yD in H01 V...