Electronic Journal of Differential Equations,
Vol. 2008(2008), No. 148, pp. 1-6.

Title: A note on radial nonlinear Schrodinger systems
       with nonlinearity spatially modulated

Author: Juan Belmonte-Beitia (Univ. de Castilla, La Mancha, Spain)

Abstract:
 First, we prove that for Schrodinger radial systems
 the polar angular coordinate must satisfy  $\theta'= 0$.
 Then using  radial symmetry, we transform the system
 into a generalized Ermakov-Pinney equation and prove the existence
 of positive  periodic solutions.
  
Submitted May 13, 2008. Published October 29, 2008.
Math Subject Classifications: 35Q55, 34B15, 35Q51.
Key Words: Nonlinear Schrodinger equation; nonlinearity spatially modulated;
           Ermakov-Pinney equation; fixed point theorem.