Noncommutative scalar solitons: existence and nonexistence
  We study the variational equations for solitons in noncommutative scalar field theories in an even number of spatial dimensions. We prove the existence of spherically symmetric solutions for a sufficiently large noncommutativity parameter $\theta$ and we prove the absence of spherically symmetric solutions for small $\theta$. 
B. Durhuus, T. Jonsson and R. Nest