Abstract.We study the following Brezis-Nirenberg type critical exponent equation which is related to the Yamabe problem:where Ω is a smooth bounded domain in R N (N ≥ 3) and 2 * is the critical Sobolev exponent. We show that, if N ≥ 5, this problem has at least N +1 2 pairs of nontrivial solutions for each fixed λ ≥ λ1, where λ1 is the first eigenvalue of −Δ with the Dirichlet boundary condition. For N ≥ 3, we give energy estimates from below for ground state solutions.
Mathematics Subject Classification (2010). 35J20, 35J25, 35J60.