@article {2006, title = {Radial solutions concentrating on spheres of nonlinear Schr{\"o}dinger equations with vanishing potentials}, journal = {Proc. Roy. Soc. Edinburgh Sect. A 136 (2006) 889-907}, number = {SISSA;38/2005/M}, year = {2006}, abstract = {We prove the existence of radial solutions of 1.2) concentrating at a sphere for potentials which might be zero and might decay to zero at\\r\\ninfinity. The proofs use a perturbation technique in a variational setting, through a Lyapunov-Schmidt reduction.}, doi = {10.1017/S0308210500004789}, url = {http://hdl.handle.net/1963/1755}, author = {Antonio Ambrosetti and David Ruiz} }