Non-radial sign-changing solutions for the Schrödinger–Poisson problem in the semiclassical limit

We study the Schroedinger– Poisson problem in R^N and construct non-radial sign-changing multi-peak solutions in the semiclassical limit. The peaks are displaced in suitable symmetric configurations and collapse to the same point as the parameter ε → 0. The proof is based on the Lyapunov–Schmidt reduction