Existence of nonradial positive and nodal solutions to a critical Neumann problem in a cone
We study a critical Neumann problem in an unbounded cone Σ_ω:={tx:x∈ω and t>0}, where ω is an open connected subset of the unit sphere S^N−1 in R^N with smooth boundary, N≥3 and 2∗:=2N/N−2. We assume that some local convexity condition at the boundary of the cone is satisfied. If ω is symmetric with respect to the north pole of S^N−1, we establish the existence of a nonradial sign-changing solution.