Oscillatons formed by non linear gravity
  Oscillatons are solutions of the coupled Einstein-Klein-Gordon (EKG) equations that are globally regular and asymptotically flat. By means of a Legendre transformation we are able to visualize the behaviour of the corresponding objects in non-linear gravity where the scalar field has been absorbed by means of the conformal mapping. 
Octavio Obregon, L. Arturo Urena-Lopez and Franz E. Schunck