Bifurcation And Multiplicity Results For Nonlinear Elliptic Problems Involving Critical Sobolev Exponents

This paper deals with the problem of existence of nontrivial solutions for a nonlinear elliptic boundary value problem in which the nonlinear term involves the critical Sobolev exponent, which is associated with a loss of compactness. The motivation for investigating this type of problem comes from the fact that mathematical models of some interesting problems in geometry (Yamabe's problem) and in physics (existence of nonminimal solutions for Yang-Mills functionals) have this character and involve a lack of compactness. Variational arguments are used here to prove some bifurcation and multiplicity results for these problems.